<PAGE>   1
                                                                     EXHIBIT 4.1


                                 FIFTH AMENDMENT


                  FIFTH AMENDMENT (this "Amendment"), dated as of November 13,
2000, among INFOUSA INC., a Delaware corporation (the "Borrower"), the lenders
party to the Credit Agreement referred to below (the "Lenders"), and BANKERS
TRUST COMPANY, as Administrative Agent (the "Administrative Agent"). All
capitalized terms used herein and not otherwise defined herein shall have the
respective meanings provided such terms in the Credit Agreement referred to
below.


                                   WITNESSETH:


                  WHEREAS, the Borrower, the Lenders and the Administrative
Agent are parties to a Credit Agreement, dated as of July 23, 1999 (as amended,
modified or supplemented through, but not including, the date hereof, the
"Credit Agreement");

                  WHEREAS, the Borrower has requested the Lenders to amend
and/or waive, and the Lenders have agreed to amend and/or waive, certain
provisions of the Credit Agreement on the terms and conditions set forth herein;
and

                  WHEREAS, the parties hereto wish to amend and/or waive the
Credit Agreement on the terms and conditions set forth herein;


                  NOW, THEREFORE, it is agreed:

                  1. The Lenders hereby waive the Event of Default that has
arisen under the Credit Agreement solely as a result of the Borrower's failure
to be in compliance with Section 9.10 of the Credit Agreement for the Test
Period ended on September 30, 2000.

                  2. Section 8.18 of the Credit Agreement is hereby amended by
inserting the following new clause (e) at the end thereof:

                  "(e) Notwithstanding anything to the contrary contained in
         this Section 8.18 or elsewhere in this Agreement, neither the Borrower
         nor any Subsidiary thereof may make a Permitted Acquisition without
         first obtaining the prior written consent of the Required Lenders."

                  3. Section 8.20 of the Credit Agreement is hereby deleted and
the following new Section 8.20 is inserted in lieu thereof:

                  "8.20 Ownership in Unrestricted Subsidiaries. The Borrower
         and/or a Subsidiary Guarantor will at all times maintain an equity
         ownership interest (on a fully diluted basis) in the capital stock of
         each of info.com and BC equal to at least 35% of the total outstanding
         capital stock of each such Unrestricted Subsidiary (on a fully diluted
         basis)."



<PAGE>   2

                  4. Section 9.03 (iii) of the Credit Agreement is hereby
amended by inserting the following words at the beginning thereof:

                           "with prior written consent of the Required Lenders
                           and".

                  5. Section 9.03(v) of the Credit Agreement is hereby amended
by inserting the following words at the beginning thereof:

                           "with the prior written consent of the Required
                           Lenders,".

                  6. Section 9.05(ii) of the Credit Agreement is hereby amended
by deleting the amount "$10,000,000" appearing therein and inserting the amount
"$7,500,000" in lieu thereof.

                  7. Section 9.05(v) of the Credit Agreement is hereby amended
by inserting the following words at the beginning thereof:

                           "with the prior written consent of the Required
                           Lenders,".

                  8. Section 9.05(xvi) of the Credit Agreement is hereby deleted
and the following new Section 9.05(xvi) is inserted in lieu thereof:

                           "(xiv) so long as no Default or Event of Default then
                           exists or would result therefrom, the Borrower and
                           its Subsidiaries may make additional Investments so
                           long as the aggregate amount of all such Investments
                           made pursuant to this clause (xvi) does not exceed
                           (i) $10,000,000 in fiscal year 2000, of which no more
                           than $2,000,000 may be made in the fourth fiscal
                           quarter of such fiscal year, (ii) $2,500,000 in
                           fiscal year 2001 and (iii) $1,000,000 in each fiscal
                           year thereafter (in each case, determined without
                           regard to any write-downs or write-offs thereof),
                           provided, however, neither the Borrower nor any
                           Subsidiary thereof may purchase any capital stock of
                           info.com from any shareholder thereof pursuant to
                           this clause (xvi)."

                  9. Section 9.07(a) of the Credit Agreement is hereby amended
by deleting the table appearing therein and inserting the following new table in
lieu thereof:

<TABLE>
<CAPTION>
                 "Fiscal Year Ending On                                Amount
                 ----------------------                                ------
<S>                                                                 <C>
                 December 31, 2000                                  $25,000,000
                 December 31, 2001                                  $15,000,000
                 December 31, 2002                                  $18,000,000
                 December 31, 2003                                  $18,000,000
                 December 31, 2004                                  $18,000,000
                 December 31, 2005                                  $18,000,000
                 December 31, 2006                                  $18,000,000
</TABLE>



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                  10. Section 9.08 of the Credit Agreement is hereby amended by
deleting the table appearing therein and inserting the following new table in
lieu thereof:

<TABLE>
<CAPTION>
                 "Fiscal Quarter Ending On                                 Ratio
                 -------------------------                                 -----
<S>                                                                     <C>
                 September 30, 1999                                      3.00:1.00
                 December 31, 1999                                       3.00:1.00
                 March 31, 2000                                          3.00:1.00
                 June 30, 2000                                           3.00:1.00
                 September 30, 2000                                      3.00:1.00
                 December 31, 2000                                       3.00:1.00
                 March 31, 2001                                          3.00:1.00
                 June 30, 2001                                           3.00:1.00
                 September 30, 2001                                      3.00:1.00
                 December 31, 2001                                       3.00:1.00
                 March 31, 2002  and the
                 last day of each fiscal quarter
                 of the Borrower thereafter                              3.50:1.00".
</TABLE>

                  11. Section 9.09 of the Credit Agreement is hereby amended by
deleting the table appearing therein and inserting the following new table in
lieu thereof:

<TABLE>
<CAPTION>
                 "Period                                                    Ratio
                 -------                                                    -----
<S>                                                                     <C>
                 Initial Borrowing Date through and
                 including June 29, 2000                                  4.00:1.00

                 June 30, 2000 through and including
                 September 29, 2000                                       3.75:1.00

                 September 30, 2000 through and including
                 December 30, 2000                                        3.50:1.00

                 December 31, 2000 through and including
                 March 30, 2001                                           3.25:1.00

                 March 31, 2001 through and including
                 June 29, 2001                                            3.25:1.00

                 June 30, 2001 through and including
                 September 29, 2001                                       3.15:1.00

                 September 30, 2001 through and including
                 December 30, 2001                                        3.00:1.00

                 Thereafter                                               2.75:1.00".
</TABLE>

                  12. Section 9.10 of the Credit Agreement is hereby amended by
deleting the table appearing therein and inserting the following new table in
lieu thereof:



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<TABLE>
<CAPTION>
                 "Fiscal Quarter Ending On                                 Amount
                 -------------------------                                 ------
<S>                                                                     <C>
                 December 31, 2000                                       $80,000,000
                 March 31, 2001                                          $80,000,000
                 June 30, 2001                                           $80,000,000
                 September 30, 2001                                      $80,000,000
                 December 31, 2001                                       $85,000,000
                 March 31, 2002                                          $90,000,000
                 June 30, 2002                                           $90,000,000
                 September 30, 2002                                      $90,000,000
                 December 31, 2002                                       $90,000,000
                 March 31, 2003                                          $90,000,000
                 June 30, 2003                                           $90,000,000
                 September 30, 2003                                      $90,000,000
                 December 31, 2003                                       $90,000,000
                 March 31, 2004 and the last
                 day of each fiscal quarter of the
                 Borrower thereafter                                     $95,000,000".
</TABLE>

                  13. The definition of "Applicable Margin" appearing in Section
11.01 of the Credit Agreement is hereby deleted and the following new definition
of "Applicable Margin" is inserted in lieu thereof:

                  "Applicable Margin" shall mean: (a) with respect to Tranche A
         Term Loans, Revolving Loans and Swingline Loans, from and after any
         Start Date to and including the corresponding End Date, the respective
         percentage per annum set forth below under the respective Type of
         Tranche A Term Loans, Revolving Loans or Swingline Loans and opposite
         the respective Level (i.e., Level 1, Level 2 or Level 3, as the case
         may be) indicated to have been achieved on the applicable Test Date for
         such Start Date (as shown on the respective officer's certificate
         delivered pursuant to Section 8.01(f) or the first proviso below):

<TABLE>
<CAPTION>
                                                       Tranche A Term Loans,            Tranche A Term
                                                          Revolving Loans                 Loans and
                                                        and Swingline Loans            Revolving Loans
                           Consolidated                    maintained as                maintained as
         Level            Leverage Ratio                  Base Rate Loans              Eurodollar Loans
         -----            --------------               ---------------------           ----------------
<S>                      <C>                          <C>                          <C>

           1       Less than 2.00:1.00                         1.75%                        2.75%

           2       Greater than or equal to
                   2.00:1.00 but less than
                   2.75:1.00                                   2.00%                        3.00%

           3       Greater than or equal to
                   2.75:1.00                                   2.25%                        3.25%
</TABLE>



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         provided, however, that if the Borrower fails to deliver the financial
         statements required to be delivered pursuant to Section 8.01(b) or (c)
         (accompanied by the officer's certificate required to be delivered
         pursuant to Section 8.01(f) showing the applicable Consolidated
         Leverage Ratio on the relevant Test Date) on or prior to the respective
         date required by such Sections, then Level 3 pricing shall apply until
         such time, if any, as the financial statements required as set forth
         above and the accompanying officer's certificate have been delivered
         showing the pricing for the respective Margin Reduction Period is at a
         level which is less than Level 3 (it being understood that, in the case
         of any late delivery of the financial statements and officer's
         certificate as so required, the Applicable Margin, if any, shall apply
         only from and after the date of the delivery of the complying financial
         statements and officer's certificate); provided further, that Level 3
         pricing shall apply at any time when any Default or Event of Default is
         in existence. Notwithstanding anything to the contrary contained in the
         immediately preceding sentence, Level 3 pricing shall apply for the
         period from the Fifth Amendment Effective Date to but not including the
         date which is the first Start Date after the Borrower's fiscal quarter
         ending on December 31, 2000; and

                  (b) with respect to Tranche B Term Loans maintained as (i)
         Base Rate Loans, a percentage per annum equal to 3.00%, and (ii)
         Eurodollar Loans, a percentage per annum equal to 4.00%.

                  Notwithstanding the foregoing, for periods prior to the Fifth
         Amendment Effective Date, all interest on each Tranche of outstanding
         Loans shall be calculated on the basis set forth in this definition as
         in effect immediately prior to giving effect to the Fifth Amendment."

                  14. The definition of "Unrestricted Subsidiary" appearing in
Section 11.01 of the Credit Agreement is hereby deleted and the following new
definition of "Unrestricted Subsidiary" is inserted in lieu thereof:

                  "Unrestricted Subsidiary" shall mean each of info.com, VYP and
         BC and each of their respective Subsidiaries provided that each such
         Person and its Subsidiaries shall only be permitted as Unrestricted
         Subsidiaries so long as (I) no such Unrestricted Subsidiary owns any
         capital stock of, or other equity interests in, or has any Lien on any
         property of, the Borrower or any Subsidiary of the Borrower other than
         a Subsidiary of an Unrestricted Subsidiary, and (II) any Indebtedness
         and other obligations of such Unrestricted Subsidiaries are
         non-recourse to the Borrower or any of its other Subsidiaries.

                  15. Section 11.01 of the Credit Agreement is hereby further
amended by inserting the following new definitions in the appropriate
alphabetical order:

                  "Fifth Amendment" shall mean the Fifth Amendment, dated as of
         November 13, 2000, to this Agreement.

                  "Fifth Amendment Effective Date" shall have the meaning
         provided in the Fifth Amendment.



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                  16. From and after the Fifth Amendment Effective Date (as
defined below), LB shall no longer constitute an Unrestricted Subsidiary and the
Borrower shall cause LB to take all actions required to be taken by a newly
created or acquired Domestic Subsidiary pursuant to Section 9.15 of the Credit
Agreement within 15 Business Days following the Fifth Amendment Effective Date.

                  17. On the Fifth Amendment Effective Date, the Total Revolving
Loan Commitment shall be permanently reduced from $30,000,000 to $25,000,000 (as
the same may be further reduced from time to time in accordance with the Credit
Agreement), with such reduction to apply proportionately to permanently reduce
the Revolving Loan Commitment of each RL Lender.

                  18. The Borrower and the Lenders hereby agree that for
purposes of calculating the financial covenants set forth in Sections 9.08, 9.09
and 9.10 of the Credit Agreement, the results of operations of the Unrestricted
Subsidiaries will be ignored from and after January 1, 2000.

                  19. In order to induce the Lenders to enter into this
Amendment, the Borrower hereby represents and warrants that (i) the
representations, warranties and agreements contained in Section 7 of the Credit
Agreement are true and correct in all material respects on and as of the Fifth
Amendment Effective Date, after giving effect to this Amendment (including as a
result of the redesignation of LB as a Subsidiary of the Borrower) (it being
understood and agreed that any representation or warranty which by its terms is
made as of a specified date shall be required to be true and correct in all
material respects only as of such specified date), (ii) there exists no Default
or Event of Default on the Fifth Amendment Effective Date, after giving effect
to this Amendment (including as a result of the redesignation of LB as a
Subsidiary of the Borrower), (iii) LB is permitted to be redesignated as a
"Restricted Subsidiary" for purposes of, and as defined in, the Senior
Subordinated Note Indenture, and (iv) LB is a Wholly-Owned Domestic Subsidiary
of the Borrower.

                  20. In order to induce the Lenders to enter into this
Amendment, the Borrower hereby agrees to pay to each Lender which executes and
delivers to the Administrative Agent a counterpart of this Amendment on or
before Noon (New York time) on November 13, 2000, a fee equal to .25% of the sum
of (I) such Lender's Revolving Loan Commitment on the Fifth Amendment Effective
Date (determined after giving effect to the reduction thereof as provided in
Section 17 of this Amendment) and (II) the aggregate outstanding principal
amount of such Lender's Term Loans on the Fifth Amendment Effective Date, with
such fee to be earned on the Fifth Amendment Effective Date and payable on the
Business Day immediately thereafter.

                  21. This Amendment is limited as specified and shall not
constitute a modification, acceptance or waiver of any other provision of the
Credit Agreement or any other Credit Document.

                  22. This Amendment may be executed in any number of
counterparts and by the different parties hereto on separate counterparts, each
of which counterparts when executed and delivered shall be an original, but all
of which shall together constitute one and the same instrument. A complete set
of counterparts shall be lodged with the Borrower and the Administrative Agent.



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<PAGE>   7

                  23. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAW
OF THE STATE OF NEW YORK.

                  24. This Amendment shall become effective on the date (the
"Fifth Amendment Effective Date") when the Borrower and the Required Lenders
shall have signed a counterpart hereof (whether the same or different
counterparts) and shall have delivered (including by way of facsimile
transmission) the same to the Administrative Agent at the Notice Office.

                  25. From and after the Fifth Amendment Effective Date, all
references in the Credit Agreement and each of the Credit Documents to the
Credit Agreement shall be deemed to be references to the Credit Agreement as
amended hereby.

                                      * * *




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                  IN WITNESS WHEREOF, each of the parties hereto has caused a
counterpart of this Amendment to be duly executed and delivered as of the date
first above written.


                                      INFOUSA INC.


                                      By  /s/ STORMY L. DEAN
                                         ---------------------------------------
                                         Name:    Stormy L. Dean
                                         Title:   Chief Financial Officer


                                      BANKERS TRUST COMPANY,
                                        Individually and as Administrative Agent


                                      By  /s/ DAVID J. BELL
                                         ---------------------------------------
                                         Name:    David J. Bell
                                         Title:   Principal


                                      US BANK NATIONAL ASSOCIATION


                                      By  /s/ KEVIN D. MUNRO
                                         ---------------------------------------
                                         Name:    Kevin D. Munro
                                         Title:   Vice President


                                      UNION BANK OF CALIFORNIA, N.A.


                                      By  /s/ HAGOP V. JAZMADARIAN
                                         ---------------------------------------
                                         Name:    Hagop V. Jazmadarian
                                         Title:   Vice President


                                      [AND OTHER PARTICIPATING LENDERS]