|Answer added on 31-8-2011: DoubleClick|
Hint: It's of Google
DoubleClick is a subsidiary of Google that develops and provides Internet ad serving services.
DoubleClick was founded in 1995 by Kevin O'Connor and Dwight Merriman. It was formerly listed as "DCLK" on the NASDAQ, and was purchased by private equity firms Hellman & Friedman and JMI Equity in July 2005. In March 2008, Google acquired DoubleClick for US$3.1 billion.