That's really nice and a clever idea. That said I think it will fail because the users will not be able to answer the 'what's in it for me' question in a positive way.
Pay-it-forward schemes tend to die after only a very few cycles (1 or less). Still, some people will do it so it would work as an extra revenue stream.
If you want to improve on the scheme you might add a 'pledge' component where you ask the users on the day they sign up that they pledge to pay it forward if the site successfully finds them a long term relationship (assuming that is what they are looking for). Then when they sign out you could remind them off their pledge. This should likely be tied to a one-time payment rather than something recurring.
Thanks for the feedback. Agree that there needs to be some exploration to making it work, and I think the idea of asking for contingent pledges is an interesting one! In one form or another, I don't see why free online services (dating or otherwise) don't periodically and methodically prompt users for contributions a little more often.
Wikipedia outright asks for donations, and certain mobile apps already ask highly engaged users to rate the app. Extending that to the next level would simply shift the prompt from "Donate to our non-profit" (Wikipedia) or "Rate this app?" (free iOS or Android app) to "Support our (free, for-profit) service with $?"
Pay-it-forward schemes tend to die after only a very few cycles (1 or less). Still, some people will do it so it would work as an extra revenue stream.
If you want to improve on the scheme you might add a 'pledge' component where you ask the users on the day they sign up that they pledge to pay it forward if the site successfully finds them a long term relationship (assuming that is what they are looking for). Then when they sign out you could remind them off their pledge. This should likely be tied to a one-time payment rather than something recurring.