Nemesis
If everyone has a perfect match, then everyone has a perfect opposite. Someone so unlike you, that meeting would be disastrous. This person is your Nemesis.

To increase the number of new users on the popular dating site OkCupid, we would create a service and viral campaign called Nemesis. Instead of the site finding only your perfect match, it will also use the same dating science to find a user's exact opposite, or Nemesis.

By adding a fun and conversational application to OkCupid, it removes the stigma of joining a dating site and replaces it with a cheeky benefit that users would be curious to check out. Once a member, users can feel free to explore the site for its core services.