<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM QUARTERLY
REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES AND EXCHANGE ACT OF
1934 FOR THE QUARTERLY PERIOD ENDED JUNE 30, 1998
</LEGEND>
<RESTATED> 
<MULTIPLIER>  1,000
       
<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   3-MOS                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1998             DEC-31-1997             DEC-31-1997
<PERIOD-START>                             APR-01-1998             JAN-01-1998             APR-01-1997             JAN-01-1997
<PERIOD-END>                               JUN-30-1998             JUN-30-1998             JUN-30-1997             JUN-30-1997
<CASH>                                         137,713                       0                       0                       0
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                    5,798                       0                       0                       0
<ALLOWANCES>                                       300                       0                       0                       0
<INVENTORY>                                        260                       0                       0                       0
<CURRENT-ASSETS>                               148,467                       0                       0                       0
<PP&E>                                          47,696                       0                       0                       0
<DEPRECIATION>                                  18,215                       0                       0                       0
<TOTAL-ASSETS>                                 292,578                       0                       0                       0
<CURRENT-LIABILITIES>                           48,102                       0                       0                       0
<BONDS>                                              0                       0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                         41                       0                       0                       0
<COMMON>                                           284                       0                       0                       0
<OTHER-SE>                                     235,449                       0                       0                       0
<TOTAL-LIABILITY-AND-EQUITY>                   292,578                       0                       0                       0
<SALES>                                              0                       0                       0                       0
<TOTAL-REVENUES>                                37,637                  66,877                  18,846                  34,564
<CGS>                                                0                       0                       0                       0
<TOTAL-COSTS>                                   18,867                  34,078                   9,991                  18,861
<OTHER-EXPENSES>                                30,591                  50,560                  16,296                  31,181
<LOSS-PROVISION>                                   591                   1,687                     837                   1,974
<INTEREST-EXPENSE>                                 621                   1,308                     444                     951
<INCOME-PRETAX>                               (12,016)                (18,420)                 (7,750)                (16,129)
<INCOME-TAX>                                         0                       0                       0                       0
<INCOME-CONTINUING>                           (11,821)                (17,761)                 (7,441)                (15,478)
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                (1,054)                 (1,054)                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                  (13,070)                (19,474)                 (7,750)                (16,129)
<EPS-PRIMARY>                                   (0.53)                  (0.82)                  (0.40)                  (0.86)
<EPS-DILUTED>                                   (0.53)                  (0.82)                  (0.40)                  (0.86)
        

</TABLE>