Wow. I had no idea that Google bought DoubleClick. They were killing it back in the late 90s. Interesting read here. G paid $3.1 Billion cash for DoubleClick in 2007 a year after paying $1.65B in stock for YouTube.
http://www.nytimes.com/2007/04/14/te...lick.html?_r=0
(sorry to go off topic)