See also: List of acquisitions by Google

Since 2001, Google has acquired several companies, mainly focusing on small start-ups.

In 2004, Google acquired a company called Keyhole, Inc., which developed a product called Earth Viewer, renamed in 2005 to Google Earth.

In February 2006, software company Adaptive Path sold Measure Map, a weblog statistics application, to Google. Registration to the service has since been temporarily disabled. The last update regarding the future of Measure Map was made on 6 April 2006 and outlined many of the known issues of the service.

In late 2006, Google bought the online video site YouTube for $1.65 billion in stock. Shortly after, on 31 October 2006, Google announced that it had also acquired JotSpot, a developer of wiki technology for collaborative Web sites.

On 13 April 2007, Google reached an agreement to acquire DoubleClick. Google agreed to buy the company for $3.1 billion.

On 2 July 2007, Google purchased GrandCentral. Google agreed to buy the company for $50 million.

On 9 July 2007, Google announced that it had signed a definitive agreement to acquire enterprise messaging security and compliance company Postini.

On August 5 2009, Google announced the purchase of video software maker On2 Technologies for $106.5 million - its first acquisition of a public company.

On 24 November 2009, Google announced the purchase of Teracent, a California based start up company, for an undisclosed price. This is another acquisition on Google's behalf in a series of advertising related purchases- AdMob, Double Click.

On 12 February 2010, Google announced the acquisition of Aardvark, a social network search engine,for $50 million; "we're looking forward to collaborating to see where we can take it"