Beginning to contemplate how Google might leverage ownership of Doubleclick will quickly give you a brain cramp. Possibilities are endless.

A story at washingtonpost.com focuses on how the combination could affect online advertising.

"It has been our vision to make Internet advertising better - less intrusive, more effective, and more useful," Sergey Brin, Google's co-founder and president for technology, said in a statement. "Together with DoubleClick, Google will make the Internet more efficient for end users, advertisers, and publishers."

Sure, Google plans to make Doubleclick a home for its advertising operations. But the first thing that comes to mind is whether Google can use Doubleclick to somehow help it become a one-stop location for buying ads across all mediums, from the Internet to the radio and, one day, onto television.

Remember that Doubleclick generated about $300 million in revenue last year, according to the New York Times. Yet, Google paid $3.1 billion for the company. That's triple the $1.1 billion it took to take DoubleClick private in 2005.

My guess is this purchase is about making money in a lot more places than only the Internet.