I was just talking about this with someone last night ^-^;
I don't like online relationships at all. They only end up in ~heartache~ for the presence of the online girlfriend/boyfriend.
I also think that a lot of times, they start off in high school/younger by people who aren't confident enough to approach people for dating IRL, or have no people they deem suitable for dating. It's a way to 'not feel alone'.
In my case, I did it because I didn't think there were that many gay people where I lived; therefore, I dated a guy online for about two years. But, as I matured, I realized: we probably would never get to be together. We're just from two different worlds, and either of us moving far away would put a strain on our family.
However, I'm not completely cynical: I know two guys who met on a Pokemon forum who lived in the US and the UK respectively and they made it work. They took trips to see each other. I don't know how it's going to end up..but yeah.
I think they're good to build up your confidence in that you realize you CAN be loved, and..yeah.
And, I think it's hard to fall in love online. Sure, you talk to a person nonstop, you skype, cam, etc., but..it's not the same as being in the same room as the person. It's not the same as ~being with the person~. Just..seeing them in person, going out, etc. I find you don't know a person that well until you do.
That's how my current relationship started, actually. We met on facebook, and I was going to college where he lived..and we talked a lot, and we met at a Lady Gaga concert and it was great. However, we both learned that we're not the same facade that we put up online/etc. And, now we're pretty much together all the time. XD
Overall, if you want to pursue an online relationship, go for it. I don't agree with them if it's not healthy/you don't ever get to meet.
I mean, our lives are becoming more and more intertwined with the internet and whatnot with facebook, dating websites, and even forums. People who would never have met before now can easily meet each other. It's truly fascinating, really.