<PAGE>   1
                                                                   Exhibit 10.11

                               SUBLEASE AGREEMENT

      1.    PARTIES.

      THIS SUBLEASE AGREEMENT (the "Sublease") is made and entered into as of
this 15th day of August, 2000, by and between BEA SYSTEMS, INC., a Delaware
corporation, ("Sublandlord") and DIGITAL IMPACT, a Deleware corporation
("Subtenant").

      2.    FACTS.

      Sublandlord, as tenant, entered into a certain Lease dated April 3, 2000
(the "Master Lease") with Compaq Computer Corporation, as landlord ("Landlord")
for the leasing of a building commonly known and addressed as 5425 Stevens Creek
Blvd., Santa Clara, California 95051, as more particularly described in Section
3 and Exhibit A of the Master Lease (the "Premises").

      Sublandlord desires to sublet to Subtenant, and Subtenant desires to
sublease from Sublandlord, a portion of the Premises (as more particularly
defined below), subject to the consent of Landlord and in accordance with the
terms and conditions of this Sublease.

      In consideration of the covenants and agreements set forth herein, and for
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, Sublandlord and Subtenant covenant and agree as set forth
below.

      3.    DEMISE AND TERM.

      Sublandlord subleases to Subtenant, and Subtenant subleases from
Sublandlord, the area consisting of 17,181 rentable square feet shown on the
floor plan attached as Exhibit "A" attached hereto (the "Subleased Premises"),
which comprises all of the second (2nd) floor and certain common areas of the
Building having a total rentable area of 59,367 square feet plus 94 square feet
of Shared Area (the "Building"). For the purposes of this Sublease, it is agreed
that the rentable area of the Subleased Premises and the rentable area of the
Building shall be as stated in this Section 3(a) and no variation between such
stated rentable areas and the actual rentable areas of the Subleased Premises
and/or the Building shall alter or affect the rights and obligations of
Sublandlord and Subtenant under this Sublease.

      The term of this Sublease (the "Sublease Term") shall commence on July 1,
2000 (the "Commencement Date"). The Sublease Term shall end on the earliest to
occur of (a) 11:59 p.m. on June 30, 2002, (the "Expiration Date"), (b) the date
the Sublease is sooner terminated pursuant to its terms, or (c) the date the
Master Lease is sooner terminated pursuant to its terms.

      The commencement of the Sublease Term is expressly conditioned upon the
procurement of Landlord's consent to this Sublease as set forth in Section 12(b)
of this Sublease.

      4.    BASE RENT AND ADDITIONAL RENT.

      Subtenant shall pay to Sublandlord base monthly rent ("Base Monthly Rent")
for the Subleased Premises in advance without prior notice, demand, set-off,
deduction or abatement in accordance with the following schedule:



<PAGE>   2

<TABLE>
<CAPTION>
                         MONTHLY GROSS RENTAL RATE PER
          PERIOD             RENTABLE SQUARE FOOT            MONTHLY INSTALLMENT
          ------         -----------------------------       -------------------
<S>                      <C>                                 <C>
Months 1-12                         $ 6.95                       $  119,407.95

Months 13-24                        $ 7.19                       $  123,531.39
</TABLE>

      The sum of One Hundred Nineteen Thousand Four Hundred Seven and 95/100
Dollars ($119,407.95) shall be payable by Subtenant upon the execution of this
Sublease as Monthly Base Rent for the first full calendar month of the Sublease
Term. Except for the payment due upon execution of this Sublease, Monthly Base
Rent shall be due payable by Subtenant on or before the first day of each
calendar month during the Sublease Term and pro-rated for any partial month.

      Commencing on the Commencement Date and through the remainder of the
Sublease Term, Subtenant shall pay Subtenant's Proportionate Share (as defined
below) of all costs and expenses payable by Sublandlord under the Master Lease,
except for any costs associated with the license agreement attached as Exhibit C
to the Master Lease.

      "Subtenant's Proportionate Share" shall be twenty-eight and ninety-two one
hundredths percent (28.92%). If during the Sublease Term there is a change in
the rentable area of either the Subleased Premises or the Premises, then
Subtenant's Proportionate Share shall be recalculated by dividing the revised
rentable area of the Subleased Premises by the revised rentable area of the
Premises.

      In no event shall Subtenant's obligation to pay costs and expenses exceed
Subtenant's prorata share of costs and expenses due and payable by Sublandlord
under the Master Lease. Subtenant shall pay Subtenant's share of costs and
expenses as and when the same is due and payable to Landlord under the Master
Lease and no earlier. Subtenant shall be entitled to its prorata share of all
credits, if any, given by Landlord to Sublandlord for Sublandlord's and/or
Subtenant's overpayment of costs and expenses.

      Subtenant shall pay to Sublandlord, within twenty (20) days after invoice
therefor by Sublandlord Subtenant's Proportionate Share of all costs and
expenses ("Expenses") payable by Sublandlord under the Master Lease. Sublandlord
shall have the right to estimate such Expenses from time to time, as reasonably
determined by Sublandlord and communicated to Subtenant, and Subtenant shall pay
to Sublandlord together with each payment of Monthly Base Rent, a sum equal to
one-twelfth (1/12th) of Subtenant's Proportionate Share of the then estimated
Expenses. If Sublandlord estimates such Expenses, then within one hundred twenty
(120) days after the end of each calendar year during the Sublease Term,
Sublandlord shall furnish Subtenant with a statement setting forth the actual
Expenses for such calendar year. If the actual Expenses for such calendar year
exceed the amount theretofore estimated, Subtenant shall pay to Sublandlord,
within twenty (20) days after Sublandlord has furnished Subtenant with the
statement described above, Subtenant's Proportionate Share of the excess of the
actual Expenses for such calendar year over and above the estimated Expenses.
Conversely, if the Expenses for such calendar year are less than the amount
theretofore estimated, Sublandlord shall (1) apply such excess to any amount
then owed by Subtenant to Sublandlord, or (2) credit the difference against the
next payment of Monthly Base Rent due under this Sublease, or (3) if the
Sublease Term has ended, pay such excess to Subtenant within twenty (20) days
after Sublandlord has furnished Subtenant with the statement described above.
Sublandlord may by notice to Subtenant change the estimated amount of Expenses,
in which case an appropriate payment or credit shall be made by one party to the
other within twenty (20) days after Sublandlord's notice of such change, so that
Tenant's estimated payments for the then current calendar year match Tenant's
Proportionate Share of the revised estimated Expenses for such year.



                                      -2-
<PAGE>   3

      Sublandlord will maintain accurate books and records necessary for the
determination and confirmation of the Expenses in accordance with normal
business practices, which records are to be kept for not less than two (2) years
after the calendar year to which they relate. Upon reasonable advance notice,
Subtenant shall be permitted to designate an independent certified public
accountant, reasonably approved by Sublandlord, to audit Sublandlord's books and
records. If such audit discloses any material discrepancy between Sublandlord's
prior statements of Expenses, appropriate adjustment shall be made in any
payments made by or due from Subtenant hereunder. No such audit may be conducted
with respect to a particular calendar year more than six (6) months after
delivery of Sublandlord's statement of actual Expenses for such calendar year,
unless Landlord thereafter delivers a corrected statement of actual Expenses (in
which case the deadline for Subtenant's audit shall be extended to three (3)
months after Sublandlord's delivery of the corrected statement). No person
conducting such audit shall be compensated, in whole or part, based on the
outcome of such audit.

      All amounts other than Monthly Base Rent which are payable by Subtenant to
Sublandlord pursuant to this Sublease shall be "Additional Rent," and references
in this Sublease to "Rent" shall mean both Monthly Base Rent and Additional
Rent. If any Rent due hereunder from Subtenant is not paid within five (5)
business days after notice from Sublandlord that such sum was not paid when due,
Subtenant shall be charged a late fee equal to five percent (5%) of the
delinquent amount. Said late fee shall be payable as Additional Rent and neither
Sublandlord's demand for nor collection of such late fee shall preclude
Sublandlord's exercise of all other rights and remedies arising on account of
such late payment. Subtenant acknowledges that the actual damages sustained by
virtue of late payment of Rent would be difficult or impractical to determine
and that the late fee provided above represents a reasonable estimate of such
damages

      Subtenant shall pay before delinquency all taxes and assessments levied
against Subtenant's personal property and trade or business fixtures and all
fees and charges for utilities and services supplied to the Subleased Premises
in addition to the utilities and services provided under the Master Lease.

      5.    INCORPORATION OF MASTER LEASE PROVISIONS.

      This Sublease is and shall remain subject and subordinate to the Master
Lease. Sublandlord and Subtenant shall not commit or permit to be committed on
the Subleased Premises any act or omission which shall violate any term or
condition of the Master Lease. Subtenant hereby expressly assumes and agrees to
observe, perform and otherwise comply with all covenants and obligations of the
Master Lease which pertain to the Subleased Premises (other than the obligation
to pay Rent) which are assumed by Subtenant hereunder the Sublease Term.

      Subject to the exclusions, limitations and modifications hereinbelow set
forth, the terms, covenants and conditions of the Master Lease are incorporated
in this Sublease by reference so that, except to the extent that they are
excluded, limited or otherwise modified by the provisions of this Sublease for
the purpose of incorporation by reference, each and every term, covenant and
condition of the Master Lease binding or inuring to the benefit of the Landlord
thereunder shall, in respect of this Sublease, bind or inure to the benefit of
Sublandlord, and each and every term, covenant and condition of the Master Lease
binding or inuring to the benefit of the tenant thereunder shall, in respect of
this Sublease, bind or inure to the benefit of Subtenant, with the same force
and effect as if such terms, covenants and conditions were completely set forth
in this Sublease, and as if the words "Landlord" and "Tenant," or words of
similar import, wherever the same appear in the Master Lease, were construed to
mean, respectively, "Sublandlord" and "Subtenant" in this Sublease, and as if
the word "Premises," or words of similar import, wherever the same appear in the
Master Lease, were construed to mean "Subleased Premises" in this Sublease, and
as if the word "Lease," or words of similar import, wherever the same appear in
the Master Lease, were construed to mean this "Sublease." Subtenant represents
that it has examined, read and is thoroughly familiar with the terms, covenants
and



                                      -3-
<PAGE>   4

conditions of the Master Lease, and accepts those terms, covenants and
conditions and obligations thereof which have been incorporated herein.

      The following sections of the Master Lease are not incorporated as a part
of this Sublease and are expressly excluded herefrom (except insofar as the same
may be referenced elsewhere in this Sublease for purposes of identification or
definition of certain matters): 1; 3.1; 3.4; 4.1; 4.3; 4.4; 5; 6; the first
sentence of 7.1; the first sentence of 7.2; 7.3; 18; 32; 38; 39.11; and Exhibit
H.

      The following limitations shall apply to the interpretation and
enforcement of the incorporated terms, covenants and conditions of the Master
Lease:

      The time limits contained in the Master Lease for the giving of notices,
making of demands or performing of any act, condition or covenant on the part of
the Tenant thereunder, or for the exercise by the Tenant thereunder of any
right, remedy or option, are changed for the purposes of incorporation herein by
reference by shortening the same in each instance by two (2) business days, so
that in each instance Subtenant shall have two (2) business days less time to
observe or perform hereunder than Sublandlord has as the Tenant under the Master
Lease.

      Any non-liability, release, indemnity or hold harmless provision, and any
provisions pertaining to waiver of subrogation rights and or the naming of a
party under an insurance policy, in the Master Lease for the benefit of
Landlord, that is incorporated herein by reference, shall be deemed to inure to
the benefit of Sublandlord and Landlord for the purpose of incorporation by
reference in this Sublease.

      Notwithstanding anything to the contrary contained in the Sublease or the
Master Lease, the parties hereto, including Landlord by reason of its consent
hereto, each release the others and their respective agents, employees,
successors, assignees and subtenants from all liability for injury to any person
or damage to any property that is caused by or results from a risk which is
actually insured against, which is required to be insured against under the
Master Lease or the Sublease, or which would normally be covered by "all risk"
property insurance, without regard to the negligence or willful misconduct of
the person or entity so released.

      Except to the extent caused by the negligence or willful misconduct of
Subtenant, its agents, employees, contractors or invitees, Sublandlord shall
indemnify, defend with counsel reasonably acceptable to Subtenant, and hold
Subtenant harmless from and against any and all losses, costs, claims,
liabilities and damages (including, without limitation, reasonable attorneys'
and experts' fees) caused by or arising in connection with (i) a breach of
Sublandlord's obligations under the Sublease; (ii) a breach of Sublandlord's
obligations under the Master Lease, unless caused by Subtenant's breach of its
parallel obligations under the Sublease; or (iii) the negligence or willful
misconduct of Sublandlord, its employees, contractors, agents or invitees.

      Any right of the Landlord or access or inspection and any right of the
Landlord under the Master Lease to do work in the Subleased Premises under the
Master Lease or in the Premises and any right of the Landlord in respect of
rules and regulations shall be deemed to inure to the benefit of Sublandlord and
the Landlord, for the purpose of incorporation by reference in this Sublease.

      If any of the express provisions of this Sublease shall conflict with any
of the provisions incorporated by reference, such conflict shall be resolved in
every instance in favor of the express provisions of this Sublease. If any
incorporated provision of the Master Lease cross-references a provision of the
Master Lease, which is not incorporated in this Sublease, such cross-referenced
Master Lease provision shall be disregarded except to the extent required for a
fair and equitable interpretation of the incorporated Master Lease provision.



                                      -4-
<PAGE>   5

      Any obligation of Sublandlord which is contained in this Sublease by the
incorporation by reference of the provisions of the Master Lease shall be
observed or performed by Sublandlord using reasonable good faith efforts to
cause the Landlord under the Master Lease to observe and/or perform the same,
and Sublandlord shall have a reasonable time to enforce its rights to cause such
observance or performance. Sublandlord shall not be required to furnish, supply
or install anything under any provision of the Master Lease. Subtenant shall not
in any event have any rights in respect of the Subleased Premises greater than
Sublandlord's rights under the Master Lease, and notwithstanding any provision
to the contrary, as to obligations that pertain to the Subleased Premises and
are contained in this Sublease by the incorporation by reference of the
provisions of the Master Lease, Sublandlord shall not be required to make any
payment or perform any obligation, and Sublandlord shall have no liability to
Subtenant for any matter whatsoever, except for Sublandlord's obligation to pay
the rent and additional rent due under the Master Lease and for Sublandlord's
obligation to use reasonable good faith efforts, upon request of Subtenant, to
cause the Landlord under the Master Lease to observe and/or perform Landlord's
obligations under the Master Lease. Sublandlord shall not be responsible for any
failure or interruption, for any reason whatsoever, of the services or
facilities that may be appurtenant to or supplied at the Premises by the
Landlord.

      With respect to any approval or consent required to be obtained from
Landlord under the Master Lease, such approval or consent must be obtained from
both Landlord and Sublandlord, and the approval of Sublandlord may be withheld
if Landlord's approval or consent is not obtained.

      Notwithstanding the incorporation of specific terms, covenants and
conditions of the Master Lease into this Sublease, such incorporated terms,
covenants and conditions have in instances been further modified or amended as
more particularly stated within the terms of this Sublease, including, without
limitation, the following modifications:

      The remedies available to Sublandlord in case of Subtenant's default, as
set forth in Section 19 of the Master Lease, shall include (without limitation)
those provided in California Civil Code Sections 1951.2 and 1951.4. Furthermore,
the notice and cure periods set forth in Section 19.1 of the Master Lease shall
reduced from five (5) business days and thirty (30) days, respectively, to three
(3) business days and twenty (20) days.

      If the Subleased Premises are not surrendered at the Expiration Date or
sooner termination of this Sublease in the condition required by the Master
Lease, Subtenant shall be deemed in a holdover tenancy pursuant to this Section
and Subtenant shall indemnify, defend, and hold Landlord and Sublandlord
harmless against loss or liability resulting from delay by Subtenant in so
surrendering the Subleased Premises including, without limitation, any claims
made by any succeeding tenant founded on such delay and costs incurred by
Landlord and Sublandlord in returning the Premises and the Subleased Premises to
the required condition, plus interest. Any holding over after the termination or
Expiration Date with Sublandlord's express written consent, shall be construed
as month-to-month tenancy, terminable on thirty (30) days written notice from
either party, and Subtenant shall pay as Base Monthly Rent to Sublandlord a rate
equal to one hundred fifty percent (150%) of the Base Monthly Rent due in the
month preceding the termination or Expiration Date, plus all other amounts
payable by Subtenant under this Sublease. Any holding over shall otherwise be on
the terms and conditions herein specified, except those provisions relating to
the Master Lease and this Sublease. If Subtenant remains in possession of the
Subleased Premises after the Expiration Date or sooner termination of this
Sublease without Sublandlord's consent, Subtenant's continued possession shall
be on the basis of a tenancy at sufferance and Tenant shall pay as rent during
the holdover period an amount equal to two hundred percent (200%) of the Base
Monthly Rent due in the month preceding the termination or Expiration Date, plus
all other amounts payable by Subtenant under this Sublease. This provision shall
survive the termination or expiration of the Master Lease and this Sublease.



                                      -5-
<PAGE>   6

      Any notice by Subtenant of a failure by Sublandlord to perform its
obligations under this Sublease shall be delivered both to any party requested
by Sublandlord in writing, and also to Landlord.

      6.    UTILITIES AND SERVICES.

      Subtenant shall not, except with Sublandlord's prior written consent,
which consent may be withheld in Sublandlord's sole discretion, either: (i) use
any apparatus or device in the Subleased Premises which will increase the amount
of cooling, ventilation, electricity or water supplied to the Subleased Premises
beyond that usually supplied for general office use; or (ii) connect with
electric current or water pipes any device or apparatus for the purpose of using
electrical current or water, except as such connections now exist. If
Sublandlord consents to the use and/or connection of any apparatus or device
described in clauses (i) and (ii) above, Sublandlord may install meters or
similar monitoring devices to measure the amount of utilities consumed by such
apparatus or devices and Subtenant shall pay for the cost of all work and
materials required for the installation, maintenance and use of such meters and
monitoring devices. If Sublandlord elects not to install a special meter or
monitoring device, Sublandlord shall determine the amount of additional
utilities and resources consumed by such apparatus or device based upon
Sublandlord's reasonable estimates and best judgment, and such determination,
made in good faith by Sublandlord, shall be conclusive on Subtenant. Subtenant
shall pay to Sublandlord promptly upon demand the cost of any excess use of
utilities and resources based on the rates charged by the local public utility
company or other supplier furnishing same, plus any additional expense incurred
by Sublandlord in keeping account of the foregoing and administering same.

      Sublandlord shall not be in default under this Sublease or liable for any
damages directly or indirectly arising from, nor shall the rent be abated by
reason of, any failure to provide or any reduction in any of the above services
or utilities if such failure or reduction is caused by the making of repairs or
improvements to the Premises or the Building, the installation of equipment,
acts of God or the elements, labor disturbances of any character, or any other
events or conditions whatsoever beyond the reasonable control of Sublandlord, or
rationing or restrictions on the use of said services and utilities due to
energy shortages or other causes, whether or not any of the above result from
acts or omissions of Sublandlord. Furthermore, Sublandlord shall be entitled to
cooperate voluntarily in a reasonable manner with the efforts of national, state
or local governmental bodies or utilities suppliers in reducing energy or other
resources consumption. The failure of Sublandlord to provide the utilities and
services specified in this Section shall not constitute a constructive or other
eviction of Subtenant.

      Subtenant shall pay prior to delinquency for all telephone and all other
materials and services not expressly required to be provided by Sublandlord,
which may be furnished to or used in, on or about the Subleased Premises during
the Sublease Term.

      7.    USE AND CONDITION OF PREMISES

      Subtenant shall use the Subleased Premises exclusively for general office
purposes, research and development not involving regulated hazardous materials,
marketing, ancillary storage and other incidental uses, and Subtenant shall not
use, or permit the Subleased Premises to be used, for any other use or purpose
without first obtaining Sublandlord's written approval of any change in
Subtenant's use. Sublandlord makes no representation, warranty or other
assurance to Subtenant that such use of the Subleased Premises as is authorized
by this Sublease is permitted under applicable zoning and other laws, and
Subtenant assumes all risk pertaining thereto.

      Notwithstanding the foregoing, Sublandlord warrants and represents that,
as of the Commencement Date, (i) the Premises will comply with all applicable
laws, rules, regulations, codes, ordinances, underwriters' requirements,
covenants, conditions and restrictions ("Laws"), (ii) the Premises will be in
good and clean



                                      -6-
<PAGE>   7

operating condition and repair, (iii) the electrical, mechanical, HVAC,
plumbing, sewer, elevator, loading docks and doors, and other systems serving
the Premises will be in good operating condition and repair, and (iv) the roof
of the Building will be in good condition and water-tight. Sublandlord shall,
promptly after receipt of notice from Subtenant, remedy any non-compliance with
such warranty at Sublandlord's sole cost and expense.

      Subtenant shall be permitted during the Sublease Term to use up to
fifty-three (53) parking spaces in the Building Common Area designated by
Sublandlord and Landlord as serving the Building. Such parking shall be on a
non-exclusive basis unless Sublandlord elects to designate specific parking
areas for use by Sublandlord, Subtenant and other subtenants or occupants of the
Building.

      Subtenant shall at all times observe and comply with the rules and
regulations for the Building as set forth in the Master Lease and in this
Sublease. Sublandlord shall not be liable to Subtenant for the failure of any
other occupant of the Building to observe and comply with such rules and
regulations.

      8.    ASSIGNMENT AND FURTHER SUBLETTING.

      Subtenant shall not sell, assign, mortgage, pledge, hypothecate, encumber
or otherwise transfer this Sublease or any interest therein, and shall not
sub-sublet the Subleased Premises or any part thereof, or suffer or permit the
Subleased Premises or any part thereof to be occupied by any other person (the
employees of Subtenant excepted), without the prior written consent of
Sublandlord and Landlord in each instance; and any attempt to do so without such
consent shall be voidable and, at Sublandlord's election, shall constitute a
noncurable default under this Sublease. No interest of Subtenant in this
Sublease or the Subleased Premises shall be assignable by operation of law.
Subject to the terms and conditions contained in this section, Sublandlord shall
not unreasonably withhold its consent to a voluntary assignment of this Sublease
or a subletting of the Subleased Premises.

      If Subtenant desires at any time to assign this Sublease or to sublet the
Subleased Premises or any portion thereof, Subtenant shall submit to Sublandlord
at least thirty (30) days prior to the proposed effective date of the assignment
or sub-sublease, in writing: (i) a notice of intent to assign or sub-sublease,
setting forth the proposed effective date thereof; (ii) the name of the proposed
assignee or sub-subtenant; (iii) the nature of the proposed assignee's or
sub-subtenant's business to be carried on in the Subleased Premises; (iv) the
terms and provisions of the proposed assignment or sub-sublease; and (v) such
financial information as Sublandlord and Landlord may request concerning the
proposed assignee or sub-subtenant, including recent financial statements and
bank references.

      All assignment or sub-sublease agreements shall (i) contain such terms as
are described in Subtenant's notice under this Section or as otherwise agreed by
Sublandlord, (ii) prohibit further assignments or sub-subleases except with
Sublandlord's written consent, (iii) impose the same obligations and conditions
on the assignee or sublessee as are imposed on Subtenant by this Sublease
(except as to rent and term or as otherwise agreed by Sublandlord), (iv) be
expressly subject and subordinate to each and every provision of this Sublease,
(v) have a term that expires on or before the Expiration Date or upon earlier
termination of this Sublease for any reason, (vi) provide that Subtenant and/or
the assignee or sub-sublessee shall pay Sublandlord the amount of any additional
costs or expenses incurred by Sublandlord for repairs, maintenance or otherwise
as a result of any change in the nature of occupancy caused by the assignment or
sub-sublease, and (vii) if a portion of the Subleased Premises are being
sub-subleased, provide for a legally divisible sub-sublease premises.

      Sublandlord shall be entitled to receive all Bonus Rent payable in
connection with any assignment or sub-sublease less Subtenant's reasonable costs
of sub-subleasing or assigning, including brokerage and attorneys' fees and any
tenant improvement costs (subject to payment by Sublandlord to Landlord of the



                                      -7-
<PAGE>   8

percentage of such Bonus Rent as deemed to be Excess Rent under the Master
Lease. Within fifteen (15) days after written request by Sublandlord, Subtenant
shall provide and certify to Sublandlord all financial information required for
the calculation of Bonus Rent. "Bonus Rent" means all sums received by Subtenant
in consideration for the assignment or sub-sublease (including the fair market
value, measured in dollars, of any non-cash consideration) in excess of the Rent
payable under this Sublease (prorated in case of a partial sub-sublease).

      If Sublandlord or Landlord retains the services of an attorney to review
any aspect of the proposed assignment or sub-sublease transaction, Subtenant
shall pay to Sublandlord and/or Landlord all attorneys' fees reasonably incurred
by them in connection therewith. Subtenant shall pay such attorneys' fees to
Sublandlord and/or Landlord within thirty (30) days after written request
therefor.

      No consent of Sublandlord to any assignment or sub-subletting by Subtenant
shall relieve Subtenant of the obligations to be performed by Subtenant under
this Sublease, whether accruing before or after such assignment or
sub-subletting, and notwithstanding any subsequent modification, extension or
renewal of this Sublease made with or without Subtenant's consent. The consent
by Sublandlord and Landlord to any transfer or sub-subletting shall not relieve
Subtenant from the obligations to obtain Sublandlord's and Landlord's express
prior written consent to any other transfer or sub-subletting. The acceptance by
Sublandlord of payment from any other person shall not be deemed to be a waiver
by Sublandlord of any provision of this Sublease or to be a consent to any
transfer or sub-sublease, or to be a release of Subtenant from any obligation
under this Sublease. If this Sublease is assigned, or if the Subleased Premises
or any part thereof is sub-sublet or occupied by any person other than
Subtenant, Sublandlord may, after default by Subtenant, collect the rent from
any such assignee, transferee, sub-subtenant or occupant and apply the net
amount collected to the Rent reserved herein, and no such action by Sublandlord
shall be deemed a consent to such assignment, transfer, sub-sublease or
occupancy.

      Each assignee of Subtenant shall assume all obligations of Subtenant under
this Sublease and shall be and remain liable jointly and severally with
Subtenant for the payment of the Rent and the performance of all the terms,
covenants, conditions and agreements herein contained on Subtenant's part to be
performed for the Sublease Term. No assignment shall be binding on Sublandlord
unless the assignee or Subtenant delivers to Sublandlord a counterpart of the
assignment instrument in recordable form which contains a covenant of assumption
by the transferee satisfactory in substance and form to Sublandlord, consistent
with the requirements of this section. The failure or refusal of any assignee to
execute such instrument of assumption shall not release or discharge the
assignee from its liability to Sublandlord hereunder. Sublandlord shall have no
obligation whatsoever to perform any duty to or respond to any request from any
sub-sublessee, it being the obligation of Subtenant to administer the terms of
its subleases.

      If Subtenant is a privately held corporation, or is an unincorporated
association, limited liability company or partnership, the transfer, assignment
or hypothecation of any stock or interest in such corporation, association,
limited liability company or partnership in the aggregate from the date of this
Sublease in excess of fifty percent (50%) shall be deemed an assignment or
transfer within the meaning of this section. However, nothing in this section
shall prohibit Subtenant from assigning this Sublease or sub-subletting the
Subleased Premises or any part thereof to any of the following: (a) a
subsidiary, affiliate, division or corporation controlling, controlled by or
under common control with Tenant; (b) a successor corporation related to Tenant
by merger, consolidation, or non-bankruptcy reorganization, (c) a purchaser of
substantially all of Tenant's assets located at the Premises, or (d) in the case
of a public offering of the stock of Tenant, the purchasers of Tenant's capital
stock ("Affiliate"). For purposes of the preceding sentence, the term "control"
means owning directly or indirectly fifty percent (50%) or more of the
beneficial interest in such entity, or having the direct or indirect power to
control the management policies of each person or entity, whether through
ownership, by contract or otherwise. Subtenant agrees to inform Sublandlord in
writing within thirty



                                      -8-
<PAGE>   9

(30) days of any assignment or other transfer permitted under this paragraph,
and such subletting or assignment shall not release or discharge Subtenant from
any liability under this Sublease.

      Without limiting the grounds upon which Sublandlord reasonably may
withhold consent to an assignment or further subletting, Subtenant agrees it
will be reasonable for Sublandlord to withhold consent where:

      The proposed assignee or sub-subtenant is a governmental agency or
authority, or is a direct competitor of Sublandlord;

      The proposed assignee or sub-subtenant is a business competitor of
Landlord as determined by Landlord in its sole and absolute discretion;

      The proposed assignee or sub-subtenant currently is someone with whom
Sublandlord is negotiating to sublease part of the Building;

      9.    SECURITY DEPOSIT.

      Sublandlord hereby acknowledges receipt from Subtenant the sum of One
Million Four Hundred Thirty-Two Eight Hundred Ninety-Five and 40/100 Dollars
($1,432,895.40), which Sublandlord shall retain as security for performance by
Subtenant of each of its obligations hereunder. If Subtenant fails at any time
to perform its obligations hereunder, Sublandlord may at its option apply the
Security Deposit, or so much thereof as is required, to cure Subtenant's
default, but if prior to the expiration or termination of this Master Lease,
Sublandlord depletes the Security Deposit in whole or in part, Subtenant shall
immediately restore the amount so used by Sublandlord. The Security Deposit
shall not bear interest for the benefit of Subtenant and may be commingled with
the funds of Sublandlord, and unless Sublandlord uses the same to cure a default
of Subtenant under the Sublease, or to restore the Subleased Premises to the
condition that Subtenant is required to leave at the conclusion of the term of
this Sublease, Sublandlord shall within thirty (30) days of the expiration or
termination of this Sublease, refund to Subtenant so much of the Security
Deposit as it continues to hold provided Subtenant has provided Sublandlord a
forwarding address.

      In lieu of the cash Security Deposit hereinabove provided for, Subtenant
shall have the option to deposit with Sublandlord a letter of credit (the
"Letter of Credit") in an amount equal to the Security Deposit. Any Letter of
Credit shall be in the form of an irrevocable, unconditional stand by letter of
credit, drawn on a bank that is reasonably acceptable to Sublandlord. The Letter
of Credit shall permit partial draws, and shall be assignable by Sublandlord to
any entity who assumes in writing any and all of Sublandlord's obligations under
this Sublease. The Letter of Credit shall be for an initial term of at least one
(1) year and shall be automatically renewable for successive one (1) year
periods, so that it remains outstanding for as long as this Sublease is in
effect, shall provide that upon presentation to the issuing institution of: (i)
the original letter of credit; (ii) Sublandlord's sight draft in the amount
sought to be drawn, and (iii) Sublandlord's written certification certifying,
under penalty of perjury, that Subtenant has defaulted under this sublease, that
Sublandlord has given Subtenant written notice of such default and Subtenant has
failed to cure such default within any time period provided therefor under this
sublease and that Sublandlord has incurred damages in the amount sought to be
drawn under the letter of credit and shall otherwise be in a form that is
reasonably acceptable to Sublandlord. In the event that Sublandlord wishes, from
time to time, to assign the Letter of Credit as aforesaid, but the Letter of
Credit is, pursuant to its terms or applicable law, not capable of being further
assigned, then Subtenant shall, upon written request from Sublandlord, promptly
cause the issuing bank to issue a new Letter of Credit in substitution of the
then existing Letter of Credit. In the event of any default by Subtenant under
this Sublease, Sublandlord shall be entitled to draw from the Letter of Credit
and/or apply the cash portion of the Security Deposit, to the extent of, and to
reimburse Sublandlord for, any and all damages owed to Sublandlord by Subtenant
as a result of such default, but if prior to the expiration or



                                      -9-
<PAGE>   10

termination of the Sublease, Sublandlord depletes the Security Deposit in whole
or in part, Subtenant shall immediately restore the amount so used by
Sublandlord. The Security Deposit shall not bear interest for the benefit of
Subtenant and may be commingled with the funds of Sublandlord, and unless
Sublandlord uses the same to cure a default of Subtenant under the Sublease, or
to restore the Subleased Premises to the condition that Subtenant is required to
leave at the conclusion of the term of this Sublease, Sublandlord shall within
thirty (30) days of the expiration or termination of this Sublease, refund to
Subtenant so much of the Security Deposit as it continues to hold provided
Subtenant has provided Sublandlord a forwarding address. If at any time the
Letter of Credit is due to expire or Sublandlord receives notice that it will
expire, other than due to the expiration of this Sublease, and Sublandlord has
not received written evidence of a new Letter of Credit reasonably acceptable to
Sublandlord thereof at least ten (10) days before such expiration, Sublandlord
may draw upon the Letter of Credit for the full amount thereof in which event
the proceeds shall become a cash security deposit which will thereafter be held
by Sublandlord in accordance with the provisions of this Sublease. In the event
that Sublandlord draws on the letter of credit solely due to Subtenant's failure
to renew the letter of credit at least ten (10) days before such expiration (1)
such failure to renew shall not constitute a default hereunder and (2) Subtenant
shall at any time thereafter be entitled to provide Sublandlord with a
replacement letter of credit that satisfies the requirements hereunder, at which
time Sublandlord shall return the cash proceeds of the original letter of credit
drawn by Sublandlord.

      10.   NOTICES.

      All notices required or permitted to be given hereunder or under
applicable law shall be in writing and shall be deemed served at the earlier of
(i) personal delivery (ii) the next business day when deposited with a reputable
overnight delivery service, transit prepaid (such as, but not limited to, DHL,
Federal Express and Airborne), or (iii) three (3) days after being sent by
United States certified mail, postage paid, return receipt requested, to the
following addresses:

      IF TO SUBLANDLORD:

            BEA Systems, Inc.
            2315 North First Street
            San Jose, California 95131
            Attn.:  Vice President, Real Estate and Corporate Services

            With a copy to:

            BEA Systems, Inc.
            2315 North First Street
            San Jose, California 95131
            Attn.: General Counsel

      IF TO SUBTENANT:

            Digital Impact
            5425 Stevens Creek Boulevard
            Santa Clara, California 95051
            Attention:

            With a copy to:

            Digital Impact, Inc.



                                      -10-
<PAGE>   11

            177 Bovet Road, Suite 200
            San Mateo, CA 94402
            Attn: __________________

      or to such addresses as the respective parties may from time to time
designate in writing in accordance with the terms of this Section 10.

      11.   SUBORDINATION AND ATTORNMENT

      Upon the written request of Sublandlord or Landlord, Subtenant will in
writing subordinate its rights under this Sublease to the lien of any mortgage
or deed of trust now or hereafter in force against the Subleased Premises, the
Premises, the Building or the underlying land and to all advances made or
hereafter to be made upon the security thereof, and to all extensions,
modifications and renewals thereunder. Subtenant shall also, upon Sublandlord's
request, subordinate its rights hereunder to any ground or underlying lease,
which may hereafter be executed affecting the Building and/or the underlying
land. Subtenant shall not subordinate its rights hereunder to any lien other
than that of a first mortgage or first deed of trust, except with the prior
written consent of the Mortgagee holding such first mortgage or deed of trust.

      Upon the written request of Landlord or any mortgagee or any lessor under
a ground or underlying lease, Subtenant shall attorn to Landlord or such
mortgagee or ground or underlying lessor, provided Landlord or such mortgagee or
lessor agrees that if Subtenant is not in default under this Sublease,
Subtenant's possession of the Subleased Premises in accordance with the terms of
this Sublease shall not be disturbed. Such agreement shall provide, among other
things, (a) that this Sublease shall remain in full force and effect, (b) that
Subtenant pay rent to Landlord or such mortgagee or lessor from the date of said
attornment, (c) that Landlord or such mortgagee or lessor shall not be
responsible to Subtenant under this Sublease except for obligations accruing
subsequent to the date of such attornment, and (d) that Subtenant, in the event
of foreclosure or a deed in lieu thereof or a termination of the ground or
underlying lease, will enter into a new lease with Landlord or such mortgagee,
lessor or other person having or acquiring title on the same terms and
conditions as this Sublease and for the balance of the Sublease Term.

      If any lender should require any modification of this Sublease as a
condition of loans secured by a lien on the Premises, the Building or the land
underlying the Building, or if any such modification is required as a condition
to a ground or underlying lease, Subtenant will approve and execute any such
modifications, promptly after request by Sublandlord provided no such
modification shall relate to the rent payable hereunder, the length of the Term
or otherwise materially change the rights or obligations of Sublandlord or
Subtenant.

      12.   BINDING EFFECT

      Subject to the limitations expressed in Section 8 above and this Section,
the covenants and agreements herein contained shall bind and inure to the
benefit of Sublandlord, Subtenant, and their respective executors,
administrators, successors and assigns.

      This Sublease is expressly conditioned upon the consent of Landlord to
this Sublease. If Landlord withholds consent to this Sublease, this Sublease
shall be automatically canceled and considered null and void. Furthermore, if
Sublandlord is unable to procure Landlord's consent to this Sublease within
thirty (30) days after the full execution of this Sublease by Sublandlord and
Subtenant, either party may thereafter terminate this Sublease upon three (3)
business days written notice to the other, in which case this Sublease shall
terminate unless Landlord's consent is procured before the end of such three (3)
business day period. In case of such cancellation or termination of this
Sublease, Sublandlord shall return any advance Rent or other funds paid by
Subtenant in consideration of this Sublease and Sublandlord and Subtenant
thereupon shall be



                                      -11-
<PAGE>   12

relieved of all further obligations hereunder. Notwithstanding the foregoing,
Sublandlord shall use commercially reasonable efforts to obtain Landlord's
consent to this sublease.

      In the event of any assignment or transfer of the Sublandlord's interest
under the Master Lease, which assignment or transfer may occur at any time
during the term hereof, as between Sublandlord and Subtenant, Sublandlord shall
be and hereby is entirely relieved of all covenants and obligations of
Sublandlord hereunder accruing after the date of such assignment or transfer,
provided such transferee has assumed all covenants and obligations thereafter to
be performed by Sublandlord hereunder. Sublandlord may transfer and deliver any
security of Subtenant to the transferee of the Sublandlord's interest under the
Master Lease, and thereupon Sublandlord shall be discharged from any further
liability with respect thereto.

      Notwithstanding the foregoing, Sublandlord shall (i) keep the Master Lease
in effect; (ii) not modify, amend or waive any provisions thereof or make any
election, exercise any option, right or remedy, or grant any consent or approval
thereunder without, in each instance, Subtenant's prior written consent; (iii)
pay the rent due and perform all of Sublandlord's other obligations under the
Master Lease, except to the extent that Subtenant is obligated to perform such
other obligations under the Sublease; (iv) not take any action or omit to take
any action that could cause or constitute a breach of the Master Lease or
otherwise give rise to a right of Landlord to terminate the Master Lease or
declare any provision thereof to have become ineffective; and (v) enforce
performance of all obligations of Landlord under the Master Lease. In enforcing
performance of all such obligations of Landlord, Sublandlord shall (a) upon
Subtenant's written request, immediately notify Landlord of its nonperformance
under the Master Lease and request that Landlord perform its obligations under
the Master Lease, and (b) permit Subtenant to commence a lawsuit or other action
in Subtenant's name (and assign to Subtenant any rights of Sublandlord required
in connection therewith), or commence a lawsuit or other action in Sublandlord's
name, to obtain the performance required from Landlord under the Master Lease,
provided that Subtenant pays all costs and expenses incurred in connection with
any such lawsuit or other action. Sublandlord hereby assigns to Subtenant all
warranties given and indemnities made, if any, by Landlord to Sublandlord under
the Master Lease which could reduce Subtenant's obligations hereunder, and
Sublandlord shall cooperate with Subtenant to enforce all such warranties and
indemnities.

      In the event that Sublandlord defaults in the performance or observance of
any of Sublandlord's obligations under the Master Lease, Landlord, by its
consent hereto, hereby agrees to deliver to Subtenant, at the same time and in
the same manner as delivered to Sublandlord, a copy of any notice of default
required to be delivered to Sublandlord under the Master Lease. Landlord, by its
consent hereto, further agrees that Subtenant shall have the right, but not the
obligation, on behalf of Sublandlord to cure any default stated in such notice
within the time available to Sublandlord to cure any such default under the
Master Lease, and Landlord shall accept such cure from Subtenant.

      If Landlord seeks to terminate the Master Lease because of a default or
alleged default by Sublandlord under the Master Lease, Sublandlord shall use its
reasonable good faith efforts to maintain the Master Lease in full force and
effect for the benefit of Subtenant and Sublandlord, and Sublandlord shall take
all action required to reinstate the Master Lease and/or to claim and pursue any
right of redemption or relief from forfeiture of the Master Lease (and as a
consequence thereof any forfeiture of the Sublease) to which Sublandlord may be
entitled at law or in equity.

      13.   MISCELLANEOUS

            A.    Subtenant shall have the right to have signage installed on
the directory sign, if any, provided by Sublandlord for the Building; such
signage shall be at Subtenant's cost, subject to approval by Sublandlord of the
details. Subtenant shall be responsible for maintaining its signage on the
directory and for its removal upon the Expiration Date or earlier termination of
this Sublease. In addition, Sublandlord will, at



                                      -12-
<PAGE>   13

Subtenant's sole cost, include Subtenant's name on Landlord's existing Building
monument sign and on the entrance doors of the Premises. Subtenant's name shall
appear below Landlord's and Sublandlord's and shall be no larger than either
name. All such signs shall conform to Landlord's current and future signage
specifications per the Master Lease.

            B.    Sublandlord and Subtenant each represent to the other that
they have dealt with no real estate brokers, finders, agents or salesman other
than CB Richard Ellis, Inc. and CRESA Partners. Each party agrees to hold the
other party harmless from and against all claims for brokerage commissions,
finder's fees or other compensation made by any other agent, broker, salesman or
finder as a consequence of said party's actions or dealings with such agent,
broker, salesman, or finder. Sublandlord shall pay any brokerage commission due
and payable under the written agreement concerning this Sublease between CB
Richard Ellis, Inc. and Sublandlord.

            C.    Sublandlord represents and warrants to Subtenant that, (i) to
the best of Sublandlord's knowledge, no default (or condition which will become
a default following the passage of time with or without the giving of notice)
under the Master Lease that would entitle Landlord to terminate the Master Lease
currently exists; (ii) a copy of the Master Lease attached hereto as Exhibit "B"
is true and correct copy of the Master Lease; and (iii) Sublandlord will
cooperate with the Subtenant regarding any relations with Landlord, such as the
giving or receiving of notice or regarding Landlord's rendering of services as
provided under the Master Lease as incorporated in this Sublease.

            D.    All prior understandings and agreements between the parties
hereto are merged within this Sublease. This Sublease and the provisions of the
Master Lease incorporated herein by the express terms of this Sublease
constitute the complete and exclusive agreement among the parties with respect
to the matters contained herein and supersede all prior written or oral
agreements or statements by and among the parties hereto, provided that this
Sublease shall be at all times subject to all of the terms and conditions of the
Master Lease.

            E.    This Sublease may not be changed, amended, modified, or
terminated, either orally or in any manner, other than by express agreement in
writing signed by the parties hereto, and by Landlord to the extent required by
the Master Lease.

      IN WITNESS WHEREOF, the parties hereto have caused this instrument to be
executed by hand as of the date first above written.

                                          SUBLANDLORD:

                                          BEA SYSTEMS, INC.,
                                          a Delaware corporation


                                          By:__________________________________

                                          Its:


                                          SUBTENANT:

                                          DIGITAL IMPACT
                                          a ________________ corporation



                                      -13-
<PAGE>   14

                                          By:__________________________________

                                          Its:



                                      -14-
<PAGE>   15

                                   EXHIBIT "A"

                        Floor Plan of Subleased Premises



<PAGE>   16

                                   EXHIBIT "B"

                        Additional Rules and Regulations

      1.    Sidewalks, doorways, vestibules, halls, stairways, elevator lobbies
and other similar areas in the common areas of the Building shall not be used
for the storage of materials or disposal of trash, be obstructed by subtenants,
or be used by subtenants for any purpose other than entrance to and exit from
the subtenant's premises and the Building and for going from one part of the
Building to another part of the Building and/or property.

      2.    Plumbing fixtures shall be used only for the purposes for which they
are designed, and no sweepings, rubbish, rags or other unsuitable materials
shall be disposed into them. Damage resulting to any such fixtures proven to
result from misuse by a subtenant, and not by Sublandlord's cleaning contractors
responsible for cleaning the subtenant's premises and the Building, shall be the
liability of said subtenant.

      3.    Subject to applicable provisions in the Sublease, signs,
advertisements, graphics or notices visible in or from public corridors, any
common area or public areas of the Building or from outside the Building shall
require Sublandlord's prior written approval. No part of the property may be
defaced by subtenants.

      4.    Significant movement in or out of the Building of furniture, office
equipment, or any other bulky or heavy materials shall be restricted to such
hours as Sublandlord shall reasonably designate. Sublandlord will determine the
method and routing of the movement of said items so as to ensure the safety of
all persons and property concerned and subtenant shall be responsible for all
costs and expenses associated therewith. Advance written notice of intent to
move such items must be made to the Sublandlord at least twenty-four (24) hours
before the time of such move. For non-significant movement in or out of the
Building of portable items which do not require use of dollies or other moving
equipment, notice to Sublandlord shall not be required.

      5.    No safe, heavy furniture or equipment shall be installed by
Subtenant without prior written approval by Sublandlord of the proposed weight
and location of the safe, furniture or equipment, and if such weight is
excessive, to reject such request. All heavy installations shall in all cases
stand on supporting devices capable of adequately distributing the weight, and
approved in advance by Sublandlord. Sublandlord has the right to require
subtenant to show, through calculations produced by a licensed structural
engineer at subtenant's expense that the proposed weight can be safely borne by
the structure. and reject the request if it cannot be safely supported.

      6.    Corridor doors which lead to common areas of the Building (other
than the doors opening into the elevator lobby on floors leased entirely to a
subtenant) shall be kept closed at all times except when actively used for
ingress or egress, and shall not be held or propped open.

      7.    Each subtenant shall cooperate with Sublandlord in keeping its
premises neat and clean. No subtenant shall employ any person for the purpose of
such cleaning other than the Buildings cleaning and maintenance personnel
without prior approval of Sublandlord.

      8.    The elevator lobby is to be kept neat and clean. The disposal of
trash or storage of materials in this area is prohibited.


<PAGE>   17

      9.    No vehicles, motorcycles, birds, fish or other animals (except for
Seeing Eye dogs) shall be brought into or kept in, on or about the Building.
Bicycles may be parked only in areas designated by Sublandlord.

      10.   Subtenants shall not tamper with or attempt to adjust temperature
control thermostats in their leased premises and shall not use any additional
methods of heating or air conditioning, and shall not inhibit the flow of air by
blocking diffusers or vents. Each subtenant shall use reasonable efforts to keep
all window blinds down and tilted at a 45-degree angle toward the street to help
maintain comfortable room temperatures and conserve energy.

      11.   Each subtenant will comply with all access control procedures
necessary both during business hours and after hours and on weekends.
Sublandlord will provide each subtenant with prior notice of such access control
procedures and any changes thereto promptly.

      12.   Subtenants are requested to lock all office doors leading to
corridors and to turn out all lights at the close of their working day;
provided, however, that no subtenant shall be responsible to ensure that
Sublandlord's cleaning contractor locks doors and turns out lights after
cleaning the subtenant's leased premises.

      13.   All requests for overtime air conditioning or heating shall be
submitted and paid for in accordance with procedures established by Sublandlord.
[Please specify the rate for after-hours HVAC.]

      14.   No flammable or explosive fluids or materials shall be kept or used
within the Building except for small, reasonable amounts of commonly used office
materials. Each subtenant shall comply with all building and fire codes relating
to the use of any flammable or explosive fluids or materials.

      15.   Subtenants may not make any modifications, alterations, additions or
repairs to their leased premises and may not install any furniture, fixtures or
equipment in their leased premises which is in violation of any applicable
building and/or fire code governing their leased premises or the Property. The
subtenant must obtain prior approval from Sublandlord of any such alterations,
modifications and additions and shall deliver "as-built" plans therefor to
Sublandlord, upon completion, except as otherwise permitted in the subtenant's
lease. Such alterations include, but are not limited to, any communication
equipment and associated wiring which must meet fire code. The Contractor
conducting the modifications and additions must be a licensed contractor, and
shall be subject to all rules and regulations of Sublandlord while performing
work in the Building and must obtain all necessary permits and approvals prior
to commencing the modifications and additions.

      16.   No vending machines of any type shall be allowed in subtenant space
without the prior written consent of Sublandlord.

      17.   All locks for doors in each subtenant's premises shall be provided
by Landlord or Sublandlord and no subtenant shall place any additional lock or
locks on any door in its premises without Sublandlord's written consent. All
requests for duplicate keys shall be made to Sublandlord.

      18.   No subtenant shall interfere in any way with any other subtenant's
(or their visitors') quiet enjoyment of their leased premises.

      19.   Sublandlord will not be liable or responsible for lost or stolen
money, jewelry or other personal property from any subtenant's leased area or
public areas of the Building or property.



                                      -2-
<PAGE>   18

      20.   Canvassing, peddling, soliciting and distribution of handbills in
the Building (except for activities within a subtenant's leased premises which
involve only such subtenant's employees) is prohibited. Each subtenant is
requested to notify Sublandlord if such activities occur.

      21.   All subtenants will refer all contractors, contractors'
representatives and installation technicians tendering any service to them to
Sublandlord for Sublandlord's supervision, approval and control before the
performance of any contractual services. This provision shall apply to all work
performed in the Building (other than work under contract for installation or
maintenance of the subtenant's equipment), including, but not limited to,
installations of telephones, telegraph equipment, electrical devices and
attachments, and any and all installation of every nature affecting floors,
walls, woodwork, trim, windows, ceilings, equipment and any other physical
portion of the Building.

      22.   Each subtenant and their contractors are responsible for removal of
trash resulting from large deliveries or move-ins. Such trash must be removed
from the Building and Building facilities may not be used for dumping. If such
trash is not promptly removed, Sublandlord may cause such trash to be removed at
the subtenant's sole cost and expense plus a reasonable additional charge to be
determined by Sublandlord to cover Sublandlord's administrative costs in
connection with such removal.

      23.   Subtenants may not install, leave or store equipment, supplies,
furniture or trash in the common areas of the Building (i.e., outside their
premises).

      Each subtenant shall provide Sublandlord with names and telephone numbers
of individuals who should be contacted in an emergency.

      24.   Subtenants shall comply with the Building life safety program
established by Sublandlord or Landlord, including without limitation fire
drills, training programs and fire warden staffing procedures, and shall
exercise all reasonable efforts to cause all subtenant employees, invitees and
guests to comply with such program.

      25.   Should a subtenant require telegraphic, enunciator or other
communication service, Sublandlord or Landlord will direct the electricians
where and how wires are to be introduced and placed and none shall be introduced
or placed except as Sublandlord shall approve. Electric current shall not be
used for space heaters, cooking or heating devices or similar appliances without
Sublandlord's prior written permission.

      26.   Nothing shall be swept or thrown into the corridors, halls, elevator
shafts or stairways.

      27.   No portion of any subtenant's premises shall at any time be used or
occupied as sleeping or lodging quarters, nor shall personnel occupancy loads
exceed limits reasonably established by Sublandlord for the Building.

      28.   Subtenant (including Subtenant's agents) will use Subtenant's
parking space allocation solely for the purpose of parking passenger model cars,
small vans, small trucks and motorcycles, and will comply in all respects with
any rules and regulations that may be promulgated by Sublandlord or Landlord
from time to time with respect to the parking facilities, including designation
of visitors parking and other limited parking. Subtenant will ensure that any
vehicle parked in the parking lot by Subtenant or its agents or employees will
be kept in proper repair and will not leak excessive amounts of oil or grease or
any amount of fuel or gasoline. If any parking is used by Subtenant at any time
(i) for any purpose other than parking as provided above; or (ii) in any way or
manner reasonably objectionable to Sublandlord, Sublandlord may consider such a
default under the Sublease.



                                      -3-
<PAGE>   19

      29.   Subtenant shall cooperate in all reasonable measures to conserve
electrical energy.



                                      -4-
<PAGE>   20

                                   EXHIBIT "C"

                                  Master Lease