Hm, I had profiles at several sites (cause friends or relatives had'em first lol!) and it really depends a lot on the site and the profile too!! How you write it, etc. What sort of pic (if any) there is...
Some people put up fake pics or profiles, that just seems off to me and not the real point at all.. You can write different profiles of yourself though (and all can be true!!) or just try different words and see what replies you get.. (Though some people hate that too, ha ha.. You can easily see who does the 'copy-paste' thing to reply though, or if any of your girl friends use the same site, you can compare experiences..)
I haven't met many people from online though (didn't dare to lol) - it seems sometimes like all guys seem to hit on you (and it may be difficult to choose or respond) and then you may get tired of it all/overwhelmed/disappointed in some you had thought to be maybe promising before and just give it a rest, and then it's quiet again lol..
I did meet a guy who turned out to be a good friend (with somewhat stalkerish tendencies) but then he died, sigh. I knew him for a long time online and then my sis met him first, lol. And there was a guy who turned out to be a good music contact. And a few guys that seemed to expect me to get a real job soon (which wasn't my priority at the time), they did seem pretty normal though, maybe too normal/boring for me though, hm.
The trouble for me seems to be that most guys either seem 'too normal/potentially boring' or too outlandish (possible weird stuff or red flags/deal-breakers, and I just stop writing/don't meet them). There were a few possibly interesting ones too, sometimes it just didn't develop into something more or it was bad timing or they had different standards in their profile already or whatever.. Or I was too shy to meet them or felt too pressured, lol..
A friend of mine was braver to meet a few quickly after she met them online. There were red flags in what some of them wrote to her already though. One was 'against fat women', and as she's had weight issues and was eating disorder-ish in the past, I told her to stay away.. There are usually red flags even when you chat or write e-mails.. Some people can be critical or even somewhat (verbally) abusive if you don't give'em personal info or telephone number straight away.. stay away from those too..
She's met a few she liked, one 'seemed to have low self-esteem issues' (was shorter than her and less sporty, she does a lot of sports - and the guy 'was scared of her' - her words, she wished he pursued her further cause she actually really liked him and his sense of humor!!) She met up with another guy lots of times to go hiking, and says 'she doesn't feel the chemistry', we'll see how that goes though.. She did meet guys to hang out with and overall I think she had a good experience about it..
There are also some people who met on forums or elsewhere online and seem happy together now..
I've heard some horror stories too, I think it's important to really try to get to know people and be 'safe' about meeting them in public first etc. there are guidelines online...
And of course you can use 'tricky questions' to navigate through them (I have a pretty good bull**** detector.. and usually find out stuff I don't even want to know lol - but then again I don't go to meet many lol..) I don't even give out my name anymore before getting to know someone somewhat well.. Some girls just go for the risks and make estimates 'live', from hanging out with the people.. You may wish to do a combination of both, and read about safety first!!
So meeting a guy online doesn't really mean anything by itself.. It's just another way to meet guys..