Just a quick thought—it seems to me that the economic incentive for a dating website to provide a good service is broken. Most businesses thrive on repeat business, or a regular cashflow from a subscription model. Customer retention being less expensive than customer acquisition, as any MBA could tell you.
Think about it; online dating isn't like that. If the service succeeds in bringing two customers together into a lasting relationship they're both going to be canceling their subscription, aren't they?
Inspired by this NYT article, E-Dating Bubble Springs a Leak.