In Jue 2007, Google paid $100 million for this company, which creates tools for advertisers and users to manage RSS feeds. It's still around, but RSS has become less interesting in the wake of Twitter -- which is now run by former Feedburner founder Dick Costolo.
#11: Like.com visual search, $100 million+
Google bought this visual search company last summer, and put the team to work building a search vertical for women's fashion called Boutiques.com.