APGIL and I met online, although not a dating site (we met on the SciFi message board for MST3k), and I have to say it was a pretty positive thing for us. One of the great things about internet dating is that it's based more on personality than looks, or at least it was for us. I don't know if we would have looked twice at each other if we would have initially met in person because on paper there was just nothing about us that should have possibly worked, but our personalities just clicked perfectly. It's been fourteen years and we're still very happy with each other.
I think there is probably bad things about internet dating and I don't discount them, but there is a lot of good, too. Good luck to you!