intellectual property needed to enhance its range of ser- vice offerings. Table 3-7 lists Google's key acquisitions. Google earns the majority of its revenue from advertising on its search sites. Dur- ing the first quarter of 2011, advertising revenue accounted for 97 percent of Google's total sales. Recently, Google's main competition for ad revenue has come from Face- book and from Chinese search company, Baidu. To diversify and develop new sources of revenue, Google mounted a head-on challenge to Facebook by developing Google+, a new social networking application. To differentiate itself from Facebook and attract customers, Google added features including the ability to organize friends into groups such as family, relatives, and professional contacts. Table 3-7 Google's Key Acquisitions Acquired Company: Description of Purchased Organization's Year Acquired Technologies Applied Semantics: 2003 Its product, AdSense, is the basis for Google's paid search advertising technology. Picasa: 2004 A photo sharing site. Keyhole Technologies, Software from these three organizations was used to Zipdash, Inc., develop Google Maps. and Where2, LLC: Android: 2005 Developed the now-ubiquitous mobile operating system that Google provides at no charge to mobile carriers in exchange for being the default mobile search engine on Android mobile handsets. YouTube: 2006 Initially for sharing short videos, now streams TV shows and feature-length movies. Provides a site for video ads. DoubleClick: 2007 Developed technology that automates placements of display ads for ad agencies and advertisers. Display ads are large and splashy. GrandCentral: 2007 Used for Google Voice. Also acquired GlobalP in 2007 which provided VoIP and video conferencing capabilities for mobile hardware manufacturers. AdMob: 2007 Mobile advertising network. Advertisers can use advertising networks to place ads on multiple sites simultaneously. Nontraditional Competitors: Amazon, Apple, Google, Microsoft, and Netflix Acquired Company: Description of Purchased Orga