You do know that a lot of those profiles are ghost profiles? You make one and then never go back? Plus I think the sites them selves try to lure you by using these profiles in search results to make it look like you have plenty to choose from or... my personal favorite... you get an e-mail from one of them but you have to upgrade to read it. When you do it say something like "Hi" and when you respond.. nothing. Some I services I suspect even do things like "like you" to get you to stay around.

From my point of view if I were looking, but I am not anymore due to terrible experiences,
1. Have photos that don't make you look like a serial killer. I don't know why men put up photos where they are just rolled out of bed in a t shirt looking depressed.
2. your initial hello should just be basic like "hi I am smart guy - how are you?" if that turns them off.. good to know now (usually not a real person)
3. don't push too hard to meet up in person. Let the girl do it. Makes you look like your trying to get laid or like you are trying to make sure she is "pretty".

Consider NOT using dating sites. I suspect strongly the best of the best no longer use those.