Google DoubleClick provides ad management and ad serving solutions for companies that buy, make or sell online advertising. The world's top marketers, publishers, ad networks and agencies use DoubleClick's products as the foundation for their online advertising business. With experience and expertise in ad serving, media planning, management search, rich media, video and mobile, our DoubleClick products help customers run their media digital strategy more effectively.
Source :http://id.wikipedia.org/wiki/DoubleClick