I had a relationship that worked as long as it was at a distance. When I moved to be closer to him, things fell apart. It seems most of the ones listed here as successfull are for the most part work because they were sure they wanted a face-to-face relationship but had to be apart for a while (so maybe with some it was a long while, but my point is it worked with or without the distance)

When you do get a chance to visit face-to-face, make sure it works then. When I visited the person there was something wrong, but he said we were unique and had a unique relationship. After I moved 3,000 miles he decided he didn't want a romatic relationship and I couldn't have just a friendship with him.

They work, if both people are willing to work at it.