Google Owned A Search Engine Optimization Company, DoubleClick

It's quite amazine that Google has Owned a Search Engine Optimization company Double Click, and Performics. I think this is a revolution in SEO/SEM era where topmost search and one of the biggest SEO company are together. Google paid $3.1 billion for such an ownership and tie up with Double Click. Microsoft and Yahoo also done same act as Microsoft paid $6 billion for Aquantive and Yahoo paid $680 million for the 80 percent of Right Media.
For more information you can also visit:
http://forums.site-reference.com/topic/6983/Google-Owns-an-SEO-Company/
http://www.searchenginejournal.com/what-will-google-do-with-performics/4720/