My friend wrote greasemonkey scripts for POF and OKCupid, all it does is repeatedly search for his "type", builds a list of users and then messages them just after they come online. Same thing if someone views his profile. There's a 15 minute delay for that one so he doesn't come off as creepy.

Yeah it's spammy, but surprisingly effective, I'm encouraging him to write an A/B testing module for it so he can test the effectiveness of different messages.

Contrary to what one might think he's just using this for LTRs.