The thing is that if you do come up with some new way of getting untold gazillions of people to sign up, what is to say that the people at match.com won't be ab

The thing is that if you do come up with some new way of getting untold gazillions of people to sign up, what is to say that the people at match.com won't be able take your innovation and get using it too? For instance, you could have some way of promoting users that had brought more users onto the site, e.g. if Alice gets half a dozen of her friends to sign up then Bob gets to see Alice listed prominently in the search results. The incentive for Alice could run deeper than that, maybe only if she has got her friends to join will she be able to see all of Bob's pictures or learn about his sexual tastes. There could also be advantages for Alice's friends, because Alice introduced them to the site they might get the advantages Alice has for a limited period of time. As soon as you 'gamify' people will cheat, e.g. in the above example, Alice might create half a dozen accounts, one for each of her various email addresses. Obviously you would need a method to make this not happen, and, if you solved it, you might have a competitive advantage. However, how long would you have this advantage for before some developer at match.com cloned it?