<PAGE>

                                                                   Exhibit 10.16

THIS WARRANT AND SHARES ISSUABLE UPON THE EXERCISE OF THIS WARRANT HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), NOR UNDER
ANY STATE SECURITIES LAW AND SUCH SECURITIES MAY NOT BE PLEDGED, SOLD, ASSIGNED,
HYPOTHECATED, OR OTHERWISE TRANSFERRED UNTIL (1) A REGISTRATION STATEMENT WITH
RESPECT THERETO IS EFFECTIVE UNDER THE ACT AND ANY APPLICABLE STATE SECURITIES
LAW OR (2) THE COMPANY RECEIVES AN OPINION OF COUNSEL TO THE COMPANY OR COUNSEL
TO THE HOLDER OF SUCH SECURITIES, WHICH COUNSEL AND OPINION ARE REASONABLY
SATISFACTORY TO THE COMPANY, THAT SUCH SECURITIES MAY BE PLEDGED, SOLD,
ASSIGNED, HYPOTHECATED, OR TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION
STATEMENT UNDER THE ACT AND APPLICABLE STATE SECURITIES LAWS.

THE TRANSFER OF THIS WARRANT OR SHARES ISSUABLE UPON THE EXERCISE HEREOF IS
RESTRICTED AS DESCRIBED HEREIN.

EXERCISABLE ONLY ON OR AFTER THE DATE HEREOF AND ON OR PRIOR TO 5:00 P.M. NEW
YORK CITY TIME ON NOVEMBER 30, 2003.


244,118 Warrants                                                      Number: 13
-------                                                                       --
                                                          Date: December 7, 2000
                                                                ----------------


                             WATTAGE MONITOR INC.

     This certifies that, for value received, Wattage Monitor Inc. (the
"Company"), a Nevada corporation, has issued to RHL Ventures LLC (the "Holder")
the number of Warrants (the "Warrants") specified above. Each Warrant initially
entitles the Holder to purchase, subject to the provisions of this Warrant
Certificate and the Warrant Agreement (as hereinafter defined), one fully paid
and non-assessable share of common stock of the Company, par value $.01 per
share ("Common Stock"), at any time on or after the date hereof, and prior to
5:00 p.m. (New York City time) on November 30, 2003, for an exercise price of
$0.272 per Warrant (the "Exercise Price").

     This Warrant Certificate and each Warrant represented hereby are issued
pursuant to and are subject in all respects to the terms and conditions set
forth in the Warrant Agreement (the "Warrant Agreement"), dated as of November
30, 2000 by and between the Company and the Holder. Capitalized terms used but
not otherwise defined herein shall have the meanings ascribed to such terms in
the Warrant Agreement.

     1.   Exercise of Warrants. Subject to the provisions hereof and the
          --------------------
provisions of the Warrant Agreement, this Warrant Certificate may be exercised
in whole or in part at any time from and after the date hereof and on or before
November 30, 2003. Subject to the terms of the
<PAGE>

Warrant Agreement this Warrant Certificate shall be exercised by presentation
and surrender hereof to the Company, either in person or as set forth in Section
9 of the Warrant Agreement, accompanied by (a) the Exercise Price, in cash and
(b) a duly executed Warrant Exercise Form, the form of which is attached hereto.

     2.   Payment. The Exercise Price for the purchase of the number of shares
          -------
of Common Stock shall be paid in United States dollars, by wire transfer in
immediately available funds, to an account or accounts designated in writing by
the Company.

     3.   Reservation of Shares; Preservation of Rights of Holder. The Company
          -------------------------------------------------------
hereby agrees that at all times it will maintain and reserve, free from pre-
emptive rights, such number of authorized but unissued shares of Common Stock so
that this Warrant Certificate may be exercised without additional authorization
of shares of Common Stock after giving effect to all other options, warrants,
convertible securities and other rights to acquire shares of Common Stock.

     4.   Adjustment of Exercise Price. (a) In the event that the Company shall
          ----------------------------
sell or issue shares of Common Stock at any time after the date of issuance of
this Warrant and prior to its termination, or complete an initial public
offering of its Common Stock (whichever shall occur first) at a consideration
per share less than the Exercise Price, then the Exercise Price shall be
adjusted to a new Exercise Price equal to the consideration per share received
by the Company for such Common Stock.

          (b)  If, at any time after the date hereof, the number of shares of
Common Stock outstanding is increased by a stock dividend payable in shares of
Common Stock or by a subdivision or split-up of shares of Common Stock, then,
following the record date fixed for the determination of holders of Common Stock
entitled to receive such stock dividend, subdivision or split-up, the Exercise
Price in effect at such time shall be decreased such that the aggregate number
of Common Stock issuable upon exercise of this Warrant as of such record date
shall be increased in proportion to such increase in outstanding shares.

          (c)  If, at any time after the date hereof, the number of shares of
Common Stock outstanding is decreased by a combination of the outstanding shares
of Common Stock, then, following the record date for such combination, the
Exercise Price in effect at such time shall be increased such that the aggregate
number of Common Stock issuable upon exercise of this Warrant as of such record
date shall be decreased in proportion to such decrease in outstanding shares.

          (d)  If, at any time after the date hereof, any capital
reorganization, or any reclassification of the capital stock of the Company
(other than a change in par value or from par value to no par value or from no
par value to par value or as a result of a stock dividend or subdivision, split-
up or combination of shares) or the consolidation or merger of the Company with
or into another entity (other than a consolidation or merger in which the
Company is the continuing corporation and that does not result in any change in
the Common Stock) shall be consummated, then this Warrant shall be exercisable
after such reorganization, reclassification, consolidation, merger, sale or
other disposition into the kind and number of shares of stock or other
securities or property of the Company to which the holder of the number of
shares of
<PAGE>

Common Stock (immediately prior to the time of such reorganization or
reclassification) issuable upon exercise of this Warrant would have been
entitled upon such reorganization, reclassification, consolidation, merger, sale
or other disposition. The provisions of this Section 4 shall similarly apply to
successive reorganizations or reclassifications.

          (e)  Upon any adjustment to the Exercise Price hereunder, the number
of Common Stock purchasable upon the exercise of this Warrant shall be adjusted
to the number obtained by dividing (i) an amount equal to the product of (x) the
number of Common Stock purchasable hereunder immediately prior to such
adjustment multiplied by (y) the Exercise Price immediately prior to such
adjustment, by (ii) the Exercise Price immediately after such adjustment.

          (f)  All calculations under this Section 4 shall be made to the
nearest one-thousandth of a cent ($.001) or to the nearest one-thousandth of a
share, as the case may be.

          (g)  Immediately upon any adjustment of the Exercise Price pursuant to
the terms of this Section 4, the Company shall give written notice thereof to
the Holder, setting forth in reasonable detail and certifying the calculation of
such adjustment.

     5.   Transferability. Subject to Section 12 of the Warrant Agreement, each
          ---------------
Warrant is transferable only in whole, so as to allow the Holder of each Warrant
to purchase one (1) full shares of Common Stock.  Warrants shall be transferable
only on the books of the Company maintained at the principal office of the
Company upon delivery of this Warrant Certificate, duly endorsed by the
registered Holder or by its duly authorized attorney or representative, or
accompanied by proper evidence of succession, assignment or authority to
transfer.

     6.   Exchange of Warrants. This Warrant Certificate is exchangeable, upon
          --------------------
the surrender hereof by the registered Holder at the principal office of the
Company, for a new Warrant Certificate or Warrant Certificates entitling such
registered Holder to purchase a like aggregate number of shares of Common Stock
as this Warrant Certificate entitles such registered Holder to purchase.  A
registered Holder desiring to exchange this Warrant Certificate shall make such
request in writing delivered to the Company, and shall surrender, properly
endorsed, this Warrant Certificate to be so exchanged. Thereupon, the Company
shall deliver to the registered Holder a new Warrant Certificate or Warrant
Certificates as so requested, in the name of such registered Holder, subject to
the limitations provided in the Warrant Agreement. No fractional Warrant
Certificate shall be issued and no new Warrant Certificate entitling the
registered Holder thereof to purchase fractional shares will be issued.

     7.   Termination. This Warrant Certificate, all rights conferred hereby and
          -----------
the Warrants issuable hereunder shall terminate at 5:00 p.m. New York City time
on November 30, 2003. Any Warrants outstanding at such time shall be void and
shall no longer be exercisable.

     8.   Governing Law. This Warrant Certificate shall be governed by, and
          -------------
interpreted in accordance with, the laws of the State of New York, without
regard to such state's internal conflicts of laws principles.
<PAGE>

     IN WITNESS WHEREOF, the Company has caused this Warrant Certificate to be
duly executed by its duly authorized officer as of the 7th day of December,
2000.

                                             WATTAGE MONITOR INC.



                                             By:  /s/ Gerald R. Alderson
                                                  --------------------------
                                                  Gerald R. Alderson
                                                  President
<PAGE>

                             Warrant Exercise Form
                             ---------------------
TO:  Wattage Monitor Inc.

     The undersigned hereby: (1) irrevocably subscribes for and offers to
purchase an aggregate of _______ shares of Common Stock of Wattage Monitor Inc.,
pursuant to Warrant No.____  heretofore issued on __________, 2000; (2) encloses
an aggregate cash payment of $_________; and (3) requests that a certificate or
certificates for the shares be issued in the name of the undersigned, or the
undersigned's designee, and delivered to the undersigned, or the undersigned
designee, at the address specified below.

     Date:                              __________________________
     Holder's Name:                     __________________________
     Taxpayer Identification Number:    __________________________
     By:                                __________________________
     Printed Name:                      __________________________
     Title:                             __________________________
     Address:                           __________________________

                                        __________________________

                                        __________________________


     Cashless Exercise (Y or N)         _________


     Note: The above signature should correspond exactly with the signature set
     forth in the Warrant Agreement, with such other signature provided by the
     Holder pursuant to the Warrant Agreement, or with the signature of the
     assignee appearing in assignment form annexed hereto.

AND, if said number of shares shall not be all the shares purchasable under the
within Warrant, a new Warrant Certificate is to be issued in the name of said
undersigned for the balance remaining of the shares purchasable thereunder less
any fraction of a share paid in cash and delivered to the address stated above.