I'd say I average about 4-5 lays per year off of OKC (been on there 3 years) and another 4-5 off POF (1 and half years). In my opinion, OKC has higher quality girls. In my experience, most of them tend to be at least college educated. On the other hand POF is full of fuglies and single moms and you really have to sift through the chaff. I did manage to find some real freaks on that website though.
What I've learned:
Bios Just keep it short and to the point. Throw some good pics in there. As long as your grammar isn't atrocious and you don't come off as a complete tool, your bio won't be a major factor in deciding attraction. It's more about not screwing up than it is about impressing people.
Numbers game All game to some extent is a numbers game. But it's much more so in the online world where every half decent girl gets flooded with messages every day. Whether or not a girl happens to take interest in you is pretty much random. That's why you can't invest too much time or effort into any particular broad.
Number close quick There's absolutely no point in messaging back and forth for very long. Do a little bit of BS fluff talk and then go for the number. Try to call instead of text....that way your charming personality can really shine through. If she's going to make you wait for that number, don't waste your time.
Setup the date quick When you call her, you must strike while the iron is hot. Remember, if she's even half decent she's probably getting flooded with messages every day. Get her out, see if you get along and if there's attraction and advance quickly. If you're not feeling it, eject ASAP. More than once, I showed up for a date only to find that the girl completely misrepresented her appearance. I did not hesitate to call these girls on their BS and I ejected immediately.
Quality I can regularly land more attractive girls in the real world. Part of this is because online dating is a massive c0ck fest. But it's also because so much of who you are cannot be communicated through a profile and through messaging back and forth. This is why online dating should only be a supplement to your real world dating.
If I had to boil online dating to down to one thing: you're basically flinging a bunch of sh*t at the wall and seeing what sticks.