I'd like to share some thoughts about this too, although I've never had a romantic long distance relationship, but I know a little about it from people close to me who have.

One of my best friends has had one for years. At first he was really crazy about her, finally he's realized (well, I helped him a little) that he had only projected his feelings into this one person on the other side of the globe at the cost of his real social life.
We mustn't forget that this is easily done, surely easier than finding and maintaining a real relationship with the great advantage that this person will never get on your nerves, since she's far far away.

On the other hand there are people who are in loving, committed relationships that are turnt into ldrs by life circumstances. My elder sister for example loves her boyfriend very much and even has a baby with him. But now he's a far away sailor on a cruise ship for half a year. I don't think it's necessary to try and explain how hard this is for both of them, but they can make it work. They have trust, they know they just belong together and they love each other and sure wouldn't do anything to endanger that.

I'm sure I could feel a lot of sympathy and friendship for people I meet online, why else would I be here? But I don't think I could fall in love with someone I've never seen with my own eyes, whose voice I've never heard, who I've never touched or smelled. Friends, good friends, best friends sure but love needs all our senses.