At least you posted tits. I'll help.
Firstly, I'm not sure if FB apps would be the best way to go - I think they're disallowed now on FB ads (someone correct me if I'm wrong). While you may make a little money off them, nothing's more frustrating than to spend lots of time & money testing, only to have your ads retro-disapproved. Try and find a solid dating site offer to promote.
Check the tracking links using an online HTTP headers checker to make sure it's not being brokered - if it is, you may want to try and go direct to the network it's being brokered from.
Unfortunately, the best way to learn as to targeting, is to blow a lot of money. I'm not sure how far you've gone with testing, but find several good images, and come up with some radically different headlines/copy. Split test them all, find out which ones are winners, and think why. What about them is making people want to click on it? Don't just look at the overall winners - even the ones that come 3rd, 4th, 5th may still have aspects that you should add in. Make subtle differences to the winners, and see how they do.
Also, another thing that you should really be doing - that a lot of people don't - is make sure your images are age targeted. There's no point in throwing a picture of someone in their thirties at a bunch of 18-25s, it's not likely to convert. If you're promoting an offer at people aged 60+, give younger ones a go, but definitely include pictures of people in their own age group in the testing. A certain level of realism has to be there.
Also, while saying "35, living in london?" etc may have used to work well, people have caught on. You've got to be more subtle. (and if you are going to employ that tactic, get the targeting right! I'm 17, and the other day I saw an ad, on a site where they had my DOB, saying they were looking for 35 year olds. I facepalmed.)
Hope I helped.
