This is going to sound trollish, but I'll take a shot anyway: in three to five years, you'll be able to replace "MySpace" in this article with "Facebook" and it'll make perfect sense.

Making money is the key. MySpace wasn't able to do it with 100 million users and Facebook won't be able to do it with a billion users. Someday, perhaps, investors will learn that it's hard to make a killing by throwing free parties. If you're Twitter or Tumblr any similar social site, learn from these mistakes! By having Pro accounts, Flickr could last for decades with a decent return rate. Twitter and Facebook, on the other hand, will burn out in a few years if they don't find a sustainable source of revenue.