It is such a cool service that VCs will keep it free forever!

They're starting to make some from sites for corporations, but the only one I know of is this:

http://ncaa.cocacolazero.com/

http://blog.posterous.com/advertising-agency-crispin-porter-...

There was a TechCrunch story that referred to it as "jumping on the revenue wagon", so they're definitely getting money out of it, but it was written by Daniel Brusilovsky, the 17-year-old intern that extorted startups, and they deleted all of his articles when they terminated him.

Edit: Google cache of the TechCrunch article: http://74.125.113.132/search?q=cache:bi6GJIQbFY0J:www.techcr...