Interesting. Given the minimum size of a Colossus cluster I find the explanation Vic gives unsatisfying. That being said I'm pretty impressed with the overall product, it is the best attempt yet to unseat Facebook, and I predict it will if Facebook can't come up with a credible response quickly.<p>The killer feature is that its blended with Gmail, and since a lot of people keep gmail open all the time it means you get notified and you see stuff. Not as common to keep one's facebook page open.