Several years ago I was part of an online group called "Cloudmakers." It was a group that had formed to collectively solve the first Alternate Reality Game called "The Beast." I contributed nothing to the final solution, but came away from the experience wanting to use the internet to tell a story in the same way, taking audience members from one site to another, letting each find a path through the story.
Now of course everything is about social media, which makes this even easier - I've followed several people online, first on Livejournal, later on Facebook.