Here's what someone pointed out to me a while back in this thread: any girl who is mildly attractive (hell, a lot of the ugly ones too) gets fucking inundated with messages. Think of it like a buffet. Sure, she may have tried you on her first trip up, and hell she may have even liked you somewhat, but there are so many other options for her to choose from, unless you were really fucking good she's probably going to try something else.
Either way I have figured out that a first date means fuck all in regards to future dates. Out of the handful of dates I've gone on since using the site, only one of them was an objectively awful "date", but only one resulted in seeing the girl more.
Basically, it's not that you're selling a bad product, but the market is fucking saturated. The only way to gain some sort of advantage (aside from being ridiculously attractive and/or rich) is through sheer numbers. If only 50% of the girls respond to your messages, and then only 50% of those result in dates, and only 25% of those result in a series of dates...you get where I'm going.
And another thing, because why not: don't get tunnel vision. I've fallen prey to this too many times, but just because you're actually having a conversation with a girl and it seems to be going well, keep talking to other women. What's worse than a date not panning out? A date not panning out and you have no other options.
Half of this post isn't really directed at you since you seem to be able to get dates, but I figured I'd post it.