From library house

"Yahoo had half as many acquisitions and they seemed to be more focused on content than technology. Companies like rivals.com (sport site), wretch (a Xanga equivalent from Taiwan), and Bix.com (American Idol on the web) appear to be aimed at purchasing audiences. This seems reasonable in a world where advertising is incredibly valuable."

It would be nice to find a site that produced a feed of acquisitions and display this type of graph automatically.

This site is very good source of information on acquisitions