I believe that internet dating can make one lose most, if not all, of the faith in humanity. Either most of the people utilizing these sites are so unskilled at writing normal messages to the guys/ladies they are interested in that they come off as completely creepy/dumb/horny-as-hell, or they are just simply expressing their true selves. In which case, I am scared for America.
Understandably, internet dating sites seek to match two singles with one another; and, understandably, for some people dating and sex come together hand in hand, but if you haven't been laid in several years and your standards have been lowered to the point of wanting to find a pair of legs in a skirt, don't declare that within the first three lines of your introductory message. A tid bit of advice: perhaps you can scramble a bit of money together, fly to Vegas and hire a girl for a night to fulfill your needs. A dating site is not really the place to clean your pipes.
You complain when women don't respond to your messages. Perhaps, they are just following a simple and sensible rule - "When you don't have anything nice to say, don't say anything at all." Sorry, bud, but if your profile picture is showing you showing off your flabby stomach in a dirty bathroom mirror and your "Looking For" section lists that you are basically willing to take any sort of human affection you can get (from new friends to random hook-ups), you're not really selling it to the ladies out there. Sure, honesty is great - do not mislead women into thinking that you are Brad Pitt's long lost brother and have six figures in your bank account. But, Jesus, how many replies do you expect to get when you live in a trailer by the river with your crazy mother and children from two failed marriages? Just think about it... if you were a decent-looking guy with a Master's degree and high hopes for the future, would YOU want to settle for a chick with more baggage than the airport storage facility?
If a woman does decide to respond to your message but says that you are not her type, please do not try to convince her otherwise. No matter how many times you say, "Yeah, that's cool. Doesn't mean that we can't still be friends.", a sensible woman will not buy into that crap and stop responding completely. Especially if that woman is clearly on the dating site in search of a romance. If you really ARE looking for long-distance buddies or a gal pal to grab a vanilla mocha latte with, you are barking up a wrong web site.
Maybe you are cute, smart, have your crap together and initiate communication with a woman with a witty, thought-out message. Maybe, upon reviewing your profile, that woman finds you to be even more intriguing and worth getting to know. Make your intentions clear - if you say that you are serious about dating someone and getting to know them better, do not sporadically disappear off the radar for weeks on end, just to reappear again later. If you really joined the site as a means of boasting your ego and you really have no intentions of dating anyone you meet online, delete your account and go meet someone at a local bar. Who has the time to get their hopes up in thinking, "Oh this guy actually seems promising." just to have you play the peek-a-boo game for your own amusement. Now I see you, now I don't.