That's not a lot of leads to be honest. You have to decide if you want to try and convert them to pay per lead which will get you a few bucks per free sign up, or pay per sale which is harder to convert but pays more obviously. Plus you have to have a dating affiliate that won't care that you're using email. You might want to try dating gold which will pay $5.00 per free sign up. Not sure how they feel about email campaigns though. Or if you want to really slum it, sign up at adultdatelink. They don't give a fuck about anything but you'll only get $2.00 per free sign up.
With 500 leads though, you'll be lucky to convert 15 of those to anything IMO.