I don't know that I ever formed a real preference, but my life shows decided bias toward online dating. I find dashingscorpio's 1 in 5 statistic very interesting -- and actually sounds quite accurate. My first serious relationship started online, and I met my husband online as well. I personally think that you actually get to know people better online, because you spend so much time just talking -- physical stuff can't get in the way. Inconsistencies tend to show themselves much faster than in person as well. When I met my husband, he and I were talking about possible marriage long before either of us knew what the other looked like -- we knew that we loved the mind we each connected with. Thankfully, we were both pleasantly surprised by physical appearance too.
My only divorce was a relationship that started in-person...I guess one really negative thing I can say about in-person is that there are so many other factors to sway you. When we first got together, I kind of felt obligated to at least try because a good friend had introduced us and EVERYONE thought we were "just perfect for each other." I love my ex's family and enjoyed spending time with his friends, so I ended up staying much longer than I otherwise might have, because losing him also meant losing all of them. Thankfully, it is the internet that has allowed me to stay in touch with his sister after he decided that one woman wasn't enough in his life, and I decided that there was no room for that kind of betrayal in my life.