The problem is not metrics driven design or marginal users. It's that OKCupid wasn't successful, and that it probably can't be. So far, there isn't a tool that

The problem is not metrics driven design or marginal users. It's that OKCupid wasn't successful, and that it probably can't be. So far, there isn't a tool that has successfully matched up looking term romantic partners with a high degree of success. That work has to come from people, and they don't get as much leverage from tools as they hoped. That's why the successful apps make it a numbers game and leave it to people to solve the actual problem of matchmaking.