How Google is making money..?

Google, One of the internet giant software company.
How it became something like that big..? 
Google was founded on September 4, 1998 by two brilliant students, Larry Page and Sergey Brin they both were studied at Stanford University. On August 19, 2004 they set a mission "to organize the world's information and make it universally accessible and useful". And they are working on.

Now its 2012...; Google is offering many services like internet search, cloud computing, software, maps, blogging, youtube, gmail and advertising technologies etc.
How does they made that it? and from where they get money...?
The answers is ADVERTISING...
Take look in below infographic, Showing Google's most expensive advertising keyword.

© 2011 WordStream, Inc.