<PAGE>   1
                                                                     EXHIBIT 4.6

                            STOCK PURCHASE AGREEMENT


         This Stock Purchase Agreement ("Agreement") is entered into by and
between Internet America, Inc., a Texas corporation (the "Corporation"), and
Jack T. Smith ("Smith"), as of August 6, 2001.

                                     RECITAL


         To provide incentive for Smith to serve as the chief executive officer
of the Corporation, the Corporation desires to issue to Smith, and Smith desires
to purchase from the Corporation, 200,000 shares of the common stock, par value
$0.01 per share (the "Common Stock"), of the Corporation on the terms and
conditions set forth in this Agreement.

         1. Issuance of Shares. The Corporation hereby issues to Smith in
exchange for the Purchase Price, 200,000 shares of Common Stock (the "Shares").
The purchase price of the Shares is $0.42 per Share for a total purchase price
of $84,000 (the "Purchase Price"). The Purchase Price shall be paid
simultaneously with the execution of this Agreement by Smith delivering to the
Corporation (i) $2,000 in cash; and (ii) a promissory note in the original
principal amount of $82,000, in the form attached hereto as Exhibit A and
incorporated by reference herein (the "Note"). The Note shall be secured by a
security interest in the Shares pursuant to a Pledge and Security Agreement in
the form attached hereto as Exhibit B and incorporated by reference herein.

         2. Delivery of Certificates. Simultaneously with the execution of this
Agreement, the Corporation shall deliver to Smith certificates evidencing the
Shares. The Shares for all purposes shall be considered issued on the date of
this Agreement.

         3. Additional Compensation. During the term of this Note while Smith is
employed by the Corporation, the Corporation shall pay to Smith as additional
compensation on or before the due date of any interest payment under the Note,
an amount which after all withholding required by applicable law equals the next
interest installment due on the Note, without regard to any interest paid upon
the exercise of the Put. Such amount may be paid by a credit to the accrued
unpaid interest on the Note. No later than January 15 of each calendar year
during the term of Smith's employment, the Corporation will pay to Smith a cash
bonus in an amount which after all withholding required by applicable law equals
the federal income tax liability of Smith not previously withheld or paid by the
Corporation for any payments described in this Section 4 (the "Gross Up
Payments"), taking into account any Gross Up Payments made during the preceding
year. For purposes of calculating the Gross Up Payments, the highest marginal
federal income tax rate applicable to individuals shall be used.

         4. Put by Smith. Commencing simultaneously with the issuance of the
Shares and continuing until the seventh anniversary of this Agreement, Smith
shall have the right and option to sell all or any portion of the Shares to the
Corporation for the price of $0.42 per share. The option granted Smith pursuant
to this Section 5 (the "Put") shall be exercised by Smith delivering written
notice of his intent to exercise to the Corporation at the address set forth in
Section 9, prior to the seventh anniversary of this Agreement. Such notice shall
specify the


<PAGE>   2


number of shares to be sold to the Corporation. Such sale and purchase shall be
closed at a time and place agreeable to the parties no later than 15 days after
receipt by the Corporation of such notice. Notwithstanding anything contained
herein, the price to be paid by the Corporation upon exercise of the Put, shall
first be applied to the outstanding balance of unpaid accrued interest and
principal on the Note, and the balance, if any, shall be paid to Smith in cash.
The Put shall apply only to the Shares and no other shares of common stock of
the Corporation, and may not be transferred or assigned by Smith. No holder of
the Shares, other than Smith, may exercise the Put.

         5. Repurchase Right. In the event that Smith's employment with the
Corporation is terminated for cause prior to the third anniversary of this
Agreement, for a period of 60 days after the date of such termination, the
Corporation shall have the right and option to purchase from Smith, at a
purchase price equal to $0.42 per share, the following number of Shares: (i) on
or prior to the first anniversary: 200,000 Shares; (ii) after the first
anniversary but on or prior to the second anniversary: 133,333 Shares; and (iii)
prior to the third anniversary: 66,666 Shares; provided, however, that such
repurchase right shall terminate immediately prior to a Change in Control of the
Corporation. The purchase price upon exercise of such option shall be applied to
the outstanding balance of unpaid accrued interest and principal upon the Note
and the balance, if any, shall be paid in cash to Smith. For purposes of this
Agreement: (a) "cause" means (i) conviction of Employee of a felony involving
fraud or moral turpitude by a court of competent jurisdiction; or (ii)
Employee's willful misconduct or gross negligence, in either event, which causes
material and demonstrable harm to the Corporation; and (b) "Change in Control"
means the occurrence of one or more of the following events:

                  (1) Any person within the meaning of Section 13(d) and 14(d)
         of the Securities Exchange Act or 1934, as amended (the "Exchange
         Act"), other than the Corporation (including its subsidiaries,
         directors or executive officers) has become the beneficial owner,
         within the meaning of Rule 13d-3 under the Exchange Act, of 50 percent
         or more of the combined voting power of the Corporation's then
         outstanding Common Stock or equivalent in voting power of any class or
         classes of the Corporation's outstanding securities ordinarily entitled
         to vote in elections of directors ("voting securities"); or

                  (2) Shares representing 50 percent or more of the combined
         voting power of the Corporation's voting securities are purchased
         pursuant to a tender offer or exchange offer (other than an offer by
         the Corporation or its subsidiaries or affiliates); or

                  (3) As a result of, or in connection with, any tender offer or
         exchange offer, merger or other business combination, sale of assets or
         contested election, or any combination of the foregoing transactions (a
         "Transaction"), the persons who were directors of the Corporation
         before the Transaction shall cease to constitute a majority of the
         Board of Directors of the Corporation or of any successor to the
         Corporation; or

                  (4) Following the date hereof, the Corporation is merged or
         consolidated with another corporation and as a result of such merger or
         consolidation less than 50 percent of the outstanding voting securities
         of the surviving or resulting corporation shall then be


                                       2
<PAGE>   3


         owned in the aggregate by the former shareholders of the Corporation,
         other than (A) any party to such merger or consolidation, or (B) any
         affiliates of any such party; or

                  (5) The Corporation transfers more than 50 percent of its
         assets, or the last of a series of transfers results in the transfer of
         more than 50 percent of the assets of the Corporation, to another
         entity that is not wholly-owned by the Corporation. For purposes of
         this subsection (v), the determination of what constitutes 50 percent
         of the assets of the Corporation shall be made by the Committee, as
         constituted immediately prior to the events that would constitute a
         change of control if 50 percent of the Corporation's assets were
         transferred in connection with such events, in its sole discretion.

         6. Registration Rights. If requested by Smith, the Corporation will
register all or any portion of the Shares, under the Securities Act of 1933 as
amended, on Form S-8 (or any successor form), including a reoffer prospectus on
Form S-3 (or any successor form). The parties intend that this Agreement
constitutes an employee benefit plan as defined in Rule 405 of Regulation C of
the Securities and Exchange Commission.

         7. Notices. All notices required or permitted hereunder shall be in
writing and shall be deemed to be delivered when delivered in person, or when
deposited in the United States mail, postage prepaid, registered or certified
mail, return receipt requested, addressed as follows:

            If to Smith:                   Jack T. Smith
                                           100 Crescent Court, Suite 1620
                                           Dallas, Texas  75201


            If to the Corporation:         Internet America, Inc.
                                           350 N. St. Paul, Suite 3000
                                           Dallas, Texas  75201
                                           Attn:  Chairman of the Board


         8. Entire Agreement. This Agreement contains the entire agreement
between the parties with respect to the subject matter hereof and supersedes all
prior agreements, understandings and statements, written or oral, with respect
thereto.

         9. Severability. In the event that one or more of the provisions of
this Agreement shall, for any reason, be held to be invalid, illegal or
unenforceable in any respect, such invalid, illegal or unenforceable provision
shall not affect any other provision hereof, and this Agreement shall be
construed as if such invalid, illegal, or unenforceable provision had never been
contained herein.

         10. Further Assurances. Smith and the Corporation agree to take all
actions reasonably necessary to effectuate the intents and purposes of this
Agreement.


                                       3
<PAGE>   4


         11. Texas Law to Apply. This Agreement shall be construed under and in
accordance with the laws of the State of Texas, and all obligations of the
parties created hereunder are performable in Dallas County, Texas.

         12. Headings. The headings used in this Agreement are used for
administrative purposes only and do not constitute substantive matter to be
considered in construing the terms of this Agreement.

         13. Parties Bound. This Agreement shall be binding upon and shall inure
to the benefit of the parties hereto and to the extent permitted by this
Agreement, their successors and assigns.

         14. Amendment. This Agreement may be amended or modified only by a
writing executed by the parties.

         15. Waiver. No term or condition of this Agreement shall be deemed to
have been waived by a party, nor shall there be any estoppel against the
enforcement by a party of any provisions of this Agreement, except by written
instrument executed by the other party. No such written waiver by a party shall
be deemed a continuing waiver unless specifically stated therein, and each such
waiver shall operate only as to the specific terms or conditions waived and
shall not constitute a waiver of such terms or conditions for the future or as
to any act other than that specifically waived.

         16. Counterparts. This Agreement may be executed in multiple
counterparts all of which shall constitute one agreement and each of which shall
constitute an original of this Agreement.

         Dated as of the date first written above.

                                 INTERNET AMERICA, INC.


                                 By: /s/ PETER C. GIBBONS
                                    --------------------------------------------
                                         Peter C. Gibbons, Vice President and
                                         Chief Operating Officer



                                     /s/ JACK T. SMITH
                                 -----------------------------------------------
                                      Jack T. Smith



                                       4