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                                                                     EXHIBIT 4.3


                          FIRST AMENDED AND RESTATED
                         REGISTRATION RIGHTS AGREEMENT

     This First Amended and Restated Registration Rights Agreement dated as of
December 5, 1999 (this "Agreement") is made by and among Braun Consulting, Inc.,
a Delaware corporation (the "Corporation"), Helene O. Amster, John D. Vairo, and
Randy Dieterle (collectively, the "ETCI Shareholders").

     WHEREAS, pursuant to a Merger Agreement (the "Merger Agreement") dated as
of December 1, 1999, by and among the Corporation, Emerging Technologies
Consultants, Inc. a Pennsylvania corporation ("ETCI"), and Helene O. Amster and
John D. Vairo, the Corporation issued to Helene O. Amster and John D. Vairo
445,225 shares of the Corporation's common stock, $0.001 par value ("Common
Stock"); and

     WHEREAS, the Corporation, Helene O. Amster and John D. Vairo are parties to
the certain Registration Rights Agreement dated as of December 1, 1999, relative
to their Common Stock; and

     WHEREAS, Randy Dieterle is currently the owner and holder of 43,200 shares
of the Common Stock; and

     WHEREAS, the Corporation and the ETCI Shareholders desire to amend and
restate the Registration Rights Agreement dated as of December 1, 1999, by
including Randy Dieterle among the ETCI Shareholders.

     NOW, THEREFORE, in consideration of the premises and the mutual covenants
and agreements herein contained, the parties hereby agree as follows:

     1.   Definitions. As used in this Agreement, the following terms shall have
          -----------
the following meanings:

            1.1  The term "Exchange Act" means the Securities Exchange Act of
1934, as amended, and the rules and regulations of the SEC issued thereunder, as
they may, from time to time, be in effect.

            1.2  The term "Holder" means any ETCI Shareholder, and any other
person or entity holding Registrable Securities.

            1.3  The terms "register," "registered," and "registration" refer to
a registration effected by preparing and filing a registration statement in
compliance with the Securities Act and the declaration or ordering of
effectiveness of such registration statement.

            1.4  The term "Registrable Securities" means (1) the Common Stock
issued to the ETCI Shareholders pursuant to the Merger Agreement; and (2) any
Common Stock of the Corporation issued as a dividend or other distribution with
respect to, or in exchange or in replacement of, such Common Stock. Any
Registrable Securities will cease to be such when (i) a registration statement
covering such Registrable Securities has been declared effective by the SEC and
such Registrable Securities have been disposed of pursuant to such effective
registration statement, (ii) such Registrable Securities are distributed to the
public pursuant to Rule 144 (or any similar provision then in force) under the
Securities Act, or (iii) such Registrable Securities may be resold without any
restriction under the Securities Act.

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            1.5  The term "SEC" means the Securities and Exchange Commission.

            1.6  The term "Securities Act" means the Securities Act of 1933, as
amended, and the rules and regulations of the SEC issued thereunder, as they
may, from time to time, be in effect.

     Capitalized terms used, but not otherwise defined, in this Agreement shall
have the meanings given to them in the Merger Agreement.

     2.   Demand Registration.
          -------------------

            2.1  During the period commencing on the 181st day after the Closing
of the transaction contemplated by the Merger Agreement and ending on the 240th
day after the completion of the transaction contemplated by the Merger
Agreement, the ETCI Shareholders shall have the right to submit to the
Corporation a written notice that states the number of Registrable Securities to
be sold (a "Demand Notice") to effect a registration under the Securities Act
for up to sixty-four percent (64%) (including any shares previously registered
pursuant to Paragraph 3 hereinbelow) of the Registrable Securities held by such
ETCI Shareholder, whereupon the Corporation shall promptly give each Holder
(other than the submitting ETCI Shareholders) written notice of such Demand
Notice. Upon the irrevocable written request of any Holder (other than the
submitting ETCI Shareholder) given within twenty-one (21) days after mailing of
any such notice by the Corporation, the Corporation shall use its commercially
reasonable efforts to cause to be registered under the Securities Act all of the
Registrable Securities that each such Holder has requested be registered, up to
the limitation of the aggregate of sixty-four percent (64%) (including any
shares previously registered pursuant to Paragraph 3 hereinbelow) of the
Registrable Securities for any such Holder; and provided that the Corporation
shall not be obligated to file and cause to become effective a registration
statement under this subsection unless the aggregate number of shares of Common
Stock to be covered by such statement is 200,000 or more shares; and provided,
further, that the Corporation shall not be obligated to file and cause to become
effective more than one (1) registration statement under this subsection.

            2.2  All Registrable Securities to be sold under a registration
statement pursuant to this section shall be sold by Salomon Smith Barney, Inc.
(or any successor thereto) in an orderly process.

            2.3  Notwithstanding the foregoing, the Corporation may delay a
registration statement, and may withhold efforts to cause the registration
statement to become effective, if the Corporation determines in good faith that
such registration might (i) interfere with or affect the negotiation or
completion of any transaction that is being contemplated by the Corporation
(whether or not a final decision has been made to undertake such transaction) at
the time the right to delay is exercised, or (ii) involve initial or continuing
disclosure obligations that might not be in the best interest of the
Corporation's stockholders. If, after a registration statement becomes
effective, the Corporation advises the Holders that the Corporation considers it
appropriate for the registration statement to be amended, the Holders of such
shares shall suspend any further sales of their registered shares until the
Corporation advises them that the registration statement has been amended.

     3.   Corporation Registration.  Subject to Section 7 of this Agreement, if
          ------------------------
at any time, or from time to time, the Corporation determines to register any of
its Common Stock under the

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Securities Act in connection with the public offering of such securities for its
own account or for the accounts of other stockholders, solely for cash on a form
that would also permit the registration of the Registrable Securities (other
than on Form S-4, S-8 or any successor forms thereto) the Corporation shall,
each such time, promptly give each Holder written notice of such determination.
Upon the irrevocable written request of any Holder given within thirty (30) days
after mailing of any such notice by the Corporation, the Corporation shall use,
subject to the limitations set forth in Section 7.1, its commercially reasonable
efforts to cause to be registered under the Securities Act all of the
Registrable Securities that each such Holder has requested be registered.
Notwithstanding the foregoing, no such notice need be given of any determination
by the Corporation to register any of its Common Stock on Form S-3 (or any
successor form thereto) under the Securities Act in connection with any re-
offering or re-sale of such securities by a stockholder who or which received
such securities in connection with any merger, acquisition, consolidation or
similar transaction involving the Corporation and the Corporation shall not be
under any obligation hereunder to include in any such registration the
Registrable Securities of any Holder.

     4.   Obligations of the Corporation. Whenever required under Section 2 or 3
          ------------------------------
to use its commercially reasonable efforts to effect the registration of any
Registrable Securities, the Corporation shall, as expeditiously as reasonably
possible:

            4.1  Prepare and file with the SEC a registration statement with
respect to such Registrable Securities and use its commercially reasonable
efforts to cause such registration statement to become and remain effective;
provided, however, that in connection with any proposed registration intended to
permit an offering of any securities from time to time (i.e., a so-called "shelf
registration"), the Corporation shall in no event be obligated to cause any such
registration to remain effective for more than one hundred eighty (180) days.

            4.2  Prepare and file with the SEC such amendments and supplements
to such registration statement and the prospectus used in connection with such
registration statement as may be necessary to comply with the provisions of the
Securities Act with respect to the disposition of all securities covered by such
registration statement.

            4.3  Furnish to the Holders such numbers of copies of a prospectus,
including a preliminary prospectus, in conformity with the requirements of the
Securities Act, and such other documents as they may reasonably request in order
to facilitate the disposition of Registrable Securities owned by them.

            4.4  Use its commercially reasonable efforts to register and qualify
the securities covered by such registration statement under such other
securities or Blue Sky laws of such jurisdictions as shall be necessary for the
distribution of the securities covered by the registration statement, provided
that the Corporation shall not be required in connection therewith or as a
condition thereto to qualify to do business or to file a general consent to
service of process in any such states or jurisdictions, and further provided
that (anything in this Agreement to the contrary notwithstanding with respect to
the bearing of expenses) if any jurisdiction in which the securities shall be
qualified shall require that expenses incurred in connection with the
qualification of the securities in that jurisdiction be borne by selling
stockholders, then such expenses shall be payable by selling stockholders pro
rata, to the extent required by such jurisdiction.

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     5.   Furnish Information.  It shall be a condition precedent to the
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obligations of the Corporation to take any action pursuant to this Agreement
that the Holders shall furnish to the Corporation such information regarding
them, the Registrable Securities held by them, and the intended method of
disposition of such securities as the Corporation shall reasonably request and
as shall be required in connection with the action to be taken by the
Corporation.

     6.   Corporation Registration Expenses.  All expenses (excluding
          ---------------------------------
underwriters' discounts and commissions) incurred in connection with a
registration pursuant to Sections 2 or 3, including, without limitation, any
additional registration and qualification fees and any additional fees and
disbursements of counsel to the Corporation that result from the inclusion of
securities held by the Holders in such registration and the reasonable fees and
disbursements of one counsel for the selling Holders, shall be borne by the
Corporation.

     7.   Underwriting Requirements.
          -------------------------

            7.1  In connection with any offering involving an underwriting of
shares being issued by the Corporation, the Corporation shall not be required to
include any Registrable Securities in such underwriting unless the Holders of
such Registrable Securities accept the terms of the underwriting as agreed upon
between the Corporation and underwriters selected by it, and then only in such
quantity as will not, in the reasonable opinion of the underwriters, jeopardize
the success of the offering by the Corporation. If the total amount of
securities that all Holders or the holders of comparable registration rights
request to be included in an underwritten offering exceeds the amount of
securities that the underwriters reasonably believe compatible with the success
of the offering, the Corporation shall only be required to include in the
offering so many of the securities of the selling Holders as the underwriters
reasonably believe will not jeopardize the success of the offering (the
securities so included to be apportioned pro rata among the selling Holders and
any other selling stockholders according to the total amount of securities owned
by said selling Holders and any other selling stockholders, or in such other
proportions as shall mutually be agreed to by such selling Holders or any other
selling stockholders).

            7.2  With respect to any underwriting of shares, the Corporation
shall have the right to designate the managing underwriter or underwriters.

     8.   Delay of Registration.  No Holder shall have any right to take any
          ---------------------
action to restrain, enjoin, or otherwise delay any registration as the result of
any controversy that might arise with respect to the interpretation or
implementation of this Agreement.

     9.   Indemnification.  In the event any Registrable Securities are included
          ---------------
in a registration statement under this Agreement:

            9.1  To the extent permitted by law, the Corporation will indemnify
and hold harmless each Holder requesting or joining in a registration, any
underwriter (as defined in the Securities Act) for it, and each person, if any,
who controls such Holder or underwriter within the meaning of the Securities
Act, against any losses, claims, damages or liabilities, joint or several, to
which they may become subject under the Securities Act or otherwise, insofar as
such losses, claims, damages or liabilities (or actions in respect thereof)
arise out of or are based on any untrue or alleged untrue statement of any
material fact contained in such registration statement, including, without
limitation, any preliminary prospectus or final prospectus contained therein or
any amendments or supplements thereto, or arise out of or are based upon

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the omission or alleged omission to state therein a material fact required to be
stated therein, or necessary to make the statements therein not misleading or
arise out of any violation by the Corporation or any rule or regulation
promulgated under the Securities Act applicable to the Corporation and relating
to action or inaction required by the Corporation in connection with any such
registration; and will reimburse each such Holder, such underwriter, or
controlling person for any legal or other expenses reasonably incurred by them
in connection with investigating or defending any such loss, claim, damage,
liability, or action, provided, however, that the indemnity agreement contained
in this Section 9.1 shall not apply to amounts paid in settlement of any such
loss, claim, damage, liability or action if such settlement is effected without
the consent of the Corporation (which consent shall not be unreasonably withheld
or delayed) nor shall the Corporation be liable in any such case for any such
loss, claim, damage, liability or action to the extent that it arises out of or
is based upon an untrue statement or alleged untrue statement or omission or
alleged omission made in connection with such registration statement,
preliminary prospectus, final prospectus, or amendments or supplements thereto,
in reliance upon and in conformity with written information furnished expressly
for use in connection with such registration by any such Holder, underwriter or
controlling person.

            9.2  To the extent permitted by law, each Holder requesting or
joining in a registration will indemnify and hold harmless the Corporation, each
of its directors, each of its officers who has signed the registration
statement, each person, if any, who controls the Corporation within the meaning
of the Securities Act, and any underwriter for the Corporation (within the
meaning of the Securities Act) against any losses, claims, damages or
liabilities to which the Corporation or any such director, officer, controlling
person or underwriter may become subject, under the Securities Act or otherwise,
insofar as such losses, claims, damages or liabilities (or actions in respect
thereof) arise out of or are based upon any untrue statement or alleged untrue
statement of any material fact contained in such registration statement,
including any preliminary prospectus or final prospectus contained therein or
any amendments or supplements thereto, or arise out of or are based upon the
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading, in
each case to the extent, but only to the extent, that such untrue statement or
alleged untrue statement or omission or alleged omission was made in such
registration statement, preliminary prospectus or final prospectus, or
amendments or supplements thereto, in reliance upon and in conformity with
written information furnished by such Holder expressly for use in connection
with such registration; and will reimburse the Corporation or any such director,
officer, controlling person or underwriter for any legal or other expenses
reasonably incurred by them in connection with investigating or defending any
such loss, claim, damage, liability or action; provided, however, that the
indemnity agreement contained in this Section 9.2 shall not apply to amounts
paid in settlement of any such loss, claim, damage, liability or action if such
settlement is effected without the consent of such Holder (which consent shall
not be unreasonably withheld) and provided further that no Holder shall have any
liability under this Section 9.2 in excess of the net proceeds actually received
by such Holder in the relevant public offering.

            9.3  Promptly after receipt by an indemnified party under this
Section 9 of notice of the commencement of any action, such indemnified party
will, if a claim in respect thereof is to be made against any indemnifying party
under this Section 9, notify the indemnifying party in writing of the
commencement thereof and the indemnifying party shall have the right to
participate in, and, to the extent the indemnifying party so desires, jointly
with

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any other indemnifying party similarly noticed, to assume the defense thereof
with counsel mutually satisfactory to the parties. The failure to notify an
indemnifying party promptly of the commencement of any such action, if
prejudicial to its ability to defend such action, shall relieve such
indemnifying party of any liability to the indemnified party under this Section
9, but the omission so to notify the indemnifying party will not relieve it of
any liability that it may have to any indemnified party otherwise than under
this Section 9.

     10.  Reports Under Securities Exchange Act of 1934.  With a view to making
          ---------------------------------------------
available to the Holders the benefits of Rule 144 promulgated under the
Securities Act and any other rule or regulation of the SEC that may at any time
permit a Holder to sell securities of the Corporation to the public without
registration, the Corporation agrees that while it has a class of equity
securities registered under the Exchange Act, it will use its commercially
reasonable efforts to:

          10.1   make and keep public information available, as those terms are
understood and defined in Rule 144;

          10.2   file with the SEC in a timely manner all reports and other
documents required of the Corporation under the Securities Act and the Exchange
Act; and

          10.3   furnish to any Holder forthwith upon request a written
statement by the Corporation that it has complied with the reporting
requirements of Rule 144, a copy of the most recent annual or quarterly report
of the Corporation, and such other reports and documents so filed by the
Corporation as may be reasonably requested in availing any such holder to take
advantage of any rule or regulation of the SEC permitting the selling of any
such securities without registration.

     11.  Mergers, Etc.  The Corporation shall not, directly or indirectly,
          -------------
enter into any merger, consolidation or reorganization in which the Corporation
shall not be the surviving corporation unless the proposed surviving corporation
shall, prior to such merger, consolidation or reorganization, agree in writing
to assume the obligations of the Corporation under this Agreement, and for that
purpose references hereunder to "Registrable Securities" shall be deemed to be
references to the securities which the Holders would be entitled to receive in
exchange for Registrable Securities under any such merger, consolidation or
reorganization; provided, however, that the provisions of this Agreement shall
not apply in the event of any merger, consolidation or reorganization in which
the Corporation is not the surviving corporation if the Holders of Registrable
Securities are entitled to receive in exchange therefor (i) cash, or (ii)
securities of the acquiring corporation which may be immediately sold to the
public without registration under the Securities Act.

     12.  Notices.  All notices, requests, consents and other communications
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hereunder to any party shall be deemed to be sufficient if contained in a
written instrument delivered in person, sent by facsimile transmission with
confirmation of receipt, or duly sent by first class registered or certified
mail, postage prepaid, addressed to such party at the address set forth below or
such other address as may hereafter be designated in writing by the addressee to
the addressor listing all parties:

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          12.1   if to the Corporation, to:        with a copy to:

                 Braun Consulting, Inc.            Locke Liddell & Sapp LLP
                 30 West Monroe, Suite 300         600 Travis, 3400 Chase Tower
                 Chicago, Illinois 60603           Houston, Texas 77002
                 Attention: Steven J. Braun        Attention: Marcus A. Watts
                 Facsimile: (312) 984-7033         Facsimile: (713) 223-3717

          12.2   if to the ETCI Shareholders, to:  with a copy to:

                 Sidney E. Amster                  Kulzer & DiPadova
                 c/o Emerging Technologies         76 Euclid Avenue
                 131 Gaither Drive, Suite F        Haddonfield, New Jersey 08064
                 Mt. Laurel, New Jersey 08064      Attention: Michael A. Kulzer
                                                   Facsimile: (856) 795-8982

     13.  Miscellaneous.
          -------------

          13.1   Entire Agreement; Effect on Prior Documents. The Agreement
contains the entire agreement of the parties concerning the subject matter
hereof, and supersedes all prior negotiations, commitments, agreements and
understandings, written or oral, between or among them concerning such subject
matter.

          13.2   Amendments; Waivers. This Agreement may be amended, and
compliance with any provision of this Agreement may be omitted or waived, only
by the written agreement of the Corporation and the Holders of at least a
majority in voting power of the then-outstanding Registrable Securities.


          13.3   Governing Law. This Agreement shall be governed by, and
construed and enforced in accordance with, the substantive laws of the State of
Illinois without regard to its principles of conflicts of laws.

          13.4   Severability. Any provision of this Agreement that is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof, and any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render
unenforceable such provision in any other jurisdiction.

          13.5   Certain Matters of Construction. A reference to a Section shall
mean a Section in this Agreement unless otherwise expressly stated. The titles
and headings herein are for reference purposes only and shall not in any manner
limit the construction of this Agreement which shall be considered as a whole.
The words "include," "includes" and "including" when used herein shall be deemed
in each case to be followed by the words "without limitation." Whenever the
context may require, any pronouns used herein shall include the corresponding
masculine, feminine or neuter forms, and the singular form of names and pronouns
shall include the plural and vice-versa.

          13.6   Counterparts. This Agreement may be executed in any number of
counterparts, each such counterpart shall be deemed to be an original
instrument, and all such counterparts shall together constitute but one
agreement.

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          13.7   Third-Party Beneficiaries. This Agreement and the rights and
obligations herein shall extend to the former holders of Class B common stock of
ETCI listed on Exhibit A attached to this Agreement, and such holders shall be
third-party beneficiaries of this Agreement.

     IN WITNESS WHEREOF, the parties have executed this Registration Rights
Agreement as a contract under seal as of the date first above written.



                                    BRAUN CONSULTING, INC.


                                 By: /s/ Gregory A. Ostendorf
                                    ----------------------------------
                                    Gregory A. Ostendorf, Secretary


                                     /s/ Helene O. Amster
                                    ----------------------------------
                                    Helene O. Amster


                                    /s/ John D. Vairo
                                    ----------------------------------
                                    John D. Vairo



                                    /s/ Randy Dieterle
                                    ----------------------------------
                                    Randy Dieterle

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