Heh, yeah, I've been there. It definitely takes more than a couple tries, to be honest! Those I know who really buckle down and decide "I need a good boyfriend/girlfriend" tend to manage a few a week for a while (until finding whoever they were looking for). Now, I've never been able to keep up with that sort of pace, but you don't actually need to, just good to keep it in mind (and these are people who are experienced at finding people to go out with). Luckily, there's always new people hopping on the site. Also, I have a tendency to actually ask, pretty clearly (making sure to indicate I'm fine with it, just interested), if I think things didn't go well (only after they've refused a second date, of course! I've had things that I was sure went poorly only to find out they didn't). I've had mixed results with that, but some comments were helpful. I'm actually pretty damn terrible at dates though, which is why I don't usually go on them, and I think dedicated dates aren't really the best idea anyways (personally, different things work for different people though). I've had a lot more luck just talking and socializing online with someone for a while, getting to know their and my interests, and then inviting them to something I'm already going to do anyways, like caving or hiking or bike riding or fishing or billiards or bowling... it really depends on the girl, to be honest! And on YOU having strong hobbies and making them clear from the outset. And then be sure sure to introduce a bit of romantic tension, maybe a couple subtle innuendo, make it clear while that I enjoy being with them as friends and having fun, my intention is otherwise. You need to FLIRT. Plus, flirting can be great fun. Compliments, playful jabs, that sort of thing.
Something active, followed by something relaxing, is, in my experience, a good idea for a first date - even if it's as simple as a round of pool followed by a meal out or, even better, a meal you whip up together at one of your places. Dates based solely around passive activities like dinner and movies and stuff never did much for me - I, and most of the people I've dated, really need a bit of time together to loosen up before we are put in a situation where we have nothing to do but talk to each other, even if we've talked for weeks online.
Something good to keep in mind, if you have friends, it doesn't just have to be the two of you. A lot of times that can make things feel pretty awkward for both parties, and it might be easier if each person brings a friend or two. Sometimes one of the best options is going on some sort of public outing or trip where your communication means you actually know each other best, already, of everyone on the trip. And you're not really trapped together since there are other people around to talk to and its possible to enjoy them by yourself. Kayaking trips are good for that around here. Again, depends on you and the girl though. For some hobbies and situations that doesn't really work with, and for some girls they really want something a bit more intimate.
Mostly though, I've found its about knowing what you want and who you are, and making it very clear - answering the questions as honestly as possible and stuff and limiting your profile to things you're actually really interested in. And exploring other avenues and the like as well. Also, you read like you're desperate as well, which is never good. Take a genuine interest in the other person, enjoy them for who they are, make it clear you're looking for something more intimate (but not TOO much more intimate, people don't want to be pressured into something serious early on), and keeping up the sexual tension is a good thing even if you don't intend to have sex.