I've been following AdMob's progress since their launch, and am honestly a bit surprised that it took someone this long to acquire them. I thought you guys might enjoy reading the founder's old blog posts to see where it all started.
This post is particularly amusing: http://admob.blogspot.com/2006/01/wwgd.html
You'll notice, when looking at the early months of 2006, that AdMob attained significant growth almost immediately; sometimes things just work out.