<ARTICLE> 5
       
                                                  
<PERIOD-TYPE>                   YEAR                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1997
<PERIOD-START>                             JAN-01-1996             JAN-01-1997
<PERIOD-END>                               DEC-31-1996             JUN-30-1997
<CASH>                                      14,737,806               4,971,916
<SECURITIES>                                 4,857,163               6,523,710
<RECEIVABLES>                                3,275,518               4,352,334
<ALLOWANCES>                                   383,350                 581,219
<INVENTORY>                                     60,543                  80,270
<CURRENT-ASSETS>                            23,528,266              16,535,286
<PP&E>                                       3,462,153               5,644,834
<DEPRECIATION>                                 783,355               1,625,579
<TOTAL-ASSETS>                              26,468,158              22,147,854
<CURRENT-LIABILITIES>                        6,634,922               7,656,583
<BONDS>                                              0                 991,268
<PREFERRED-MANDATORY>                       23,153,494              23,264,467
<PREFERRED>                                    932,385                 932,385
<COMMON>                                        46,450                  88,617
<OTHER-SE>                                 (4,299,093)            (10,785,466)
<TOTAL-LIABILITY-AND-EQUITY>                26,468,158              22,147,854
<SALES>                                              0                       0
<TOTAL-REVENUES>                            14,012,388              13,366,177
<CGS>                                                0                       0
<TOTAL-COSTS>                                2,185,524               3,054,277
<OTHER-EXPENSES>                            15,843,408              17,119,451
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                   0                       0
<INCOME-PRETAX>                            (3,789,245)             (6,371,786)
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                        (3,789,245)             (6,371,786)
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                               (3,789,245)             (6,371,786)
<EPS-PRIMARY>                                        0                       0
<EPS-DILUTED>                                        0                       0