I've done online dating a few times, starting in 2006. The first time I used eHarmony, and ended up dating a guy I was matched with on there for almost a year. To be honest, I never really felt like he was "the one," and a lot of the time, I felt like he didn't get me at all... but, it was science! It was scientifically proven that we were good together! I was also one of those people terrified that I was going to be an old maid at 26. After that ended, I decided that I wanted more out of a relationship, and I'd rather pick my dates myself, thankyouverymuch.
The next round I used Match, and while I ended up going out on several dates, and a few with the same guy, nothing really great came along. I would immediately weed out anyone with egregious spelling errors and typos in their profile, or any guy whose initial message to me just said, "Hey, I like your profile." Um, maybe something a little more specific, dude? But in general, I think I was too desperate and not confident enough with myself.
But I actually met my husband on Match. I had just come off of a really bad relationship (not a Match guy! someone I met at a conference. part of the reason that he ended it--after I'd moved halfway across the country to be with him--was that I had gained about 15-20 pounds and he found me "repulsive").
So when I signed up for Match again, I didn't have a lot of expectations (though I did still use my patented weeding-out process). I was still new to the area, and I felt like it would be worth it just to get out and meet some people, check out some local restaurants, etc. I think that's partly why I had success. I certainly did not expect to meet my future spouse at that point!
So, I say--keep weeding them out, fake the confidence until you feel it, and don't let the weirdos and flaky guys get you down!