I met my wife online by total accident, neither of us were looking, we just happened to be somewhere at the same time committing the same questionable acts of file sharing and bumped into each other. 9 months and a one way ticket to the USA later we were married, we are both very happy and have an absolutely gorgeous daughter.
Meeting people online can have some definite advantages over real life. In a new relationship, plenty of good sex can often cloud the fact that you may not have much in common or even really like each other. The fact that my wife and I were able to spend all those months just sitting in front of our computers talking to each other for hours every single night was a pretty good indicator of our compatibility.
The other advantage is that you can judge people so much more efficiently. In a bar containing 50 people, it would take many hours and painful conversations to rule people out in a process of trial and error, but in a forum or chat room, you can sit back and do a quick assessment of everybody present based on what they type, it eliminates a lot of guess work.
Before it happened to me, I thought meeting people online was for losers and weirdos, but it's becoming way more common and I think it will be responsible for many strong relationships due to the meeting people from the inside out, rather than the outside in aspect of it.