<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S BALANCE SHEET AT SEPTEMBER 30, 1998 AND STATEMENTS OF INCOME FOR
THE THREE AND NINE MONTHS ENDED SEPTEMBER 30, 1998 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1998
<PERIOD-START>                             JUL-01-1998             JAN-01-1998
<PERIOD-END>                               SEP-30-1998             SEP-30-1998
<CASH>                                               0                  39,759
<SECURITIES>                                         0                       0
<RECEIVABLES>                                        0                  43,617
<ALLOWANCES>                                         0                     535
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                     0                   2,431
<PP&E>                                               0                   9,476
<DEPRECIATION>                                       0                   1,668
<TOTAL-ASSETS>                                       0                 127,339
<CURRENT-LIABILITIES>                                0                  32,206
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                             0                     168
<OTHER-SE>                                           0                  93,842
<TOTAL-LIABILITY-AND-EQUITY>                         0                 127,339
<SALES>                                              0                       0
<TOTAL-REVENUES>                                41,937                 121,831
<CGS>                                                0                       0
<TOTAL-COSTS>                                   27,867                  86,282
<OTHER-EXPENSES>                                 9,920                  25,394
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                   0                       0
<INCOME-PRETAX>                                  4,701                  11,333
<INCOME-TAX>                                     1,600                   3,985
<INCOME-CONTINUING>                              3,101                   7,348
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                     3,101                   7,348
<EPS-PRIMARY>                                     0.25                    0.63
<EPS-DILUTED>                                     0.24                    0.61
        

</TABLE>