I've hooked up with two people I met over the internet. Each situation was rather different.
The first, it was a girl who lived about 10 miles away, during my senior year of high school (she was in a different school system), so it didn't remain much of a 'virtual' courtship. But, we did meet on the internet, and chatted there for a bit before we actually met.
The second relationship was somebody I was friends with online on a MUD for a couple of years before we met at a gathering for the game. We looked up for a long-distance relationship for awhile after that, after about 6 months she moved in with me, and now, just over 6 years later, we've been married for 3.5 years.
So, it can happen.
