2004, Google became a public company via an initial public offering. At that time Larry Page, Sergey Brin, and Eric Schmidt agreed to work together at Google for 20 years, until the year 2024. The company offered 19,605,052 shares at a price of $85 per share. Shares were sold in an online auction format using a system built by Morgan Stanley and Credit Suisse, underwriters for the deal. The sale of $1.67 billion gave Google a market capitalization of more than $23 billion. On November 13, 2006, Google acquired YouTube for $1.65 billion in Google stock, On March 11, 2008, Google acquired DoubleClick for $3.1 billion, transferring to Google valuable relationships that DoubleClick had with Web publishers and advertising agencies. By 2011, Google was handling approximately 3 billion searches per day. To handle this workload, Google built 11 data centers around the world with several thousand servers in each. These data centers allowed Google to handle the ever-changing workload more efficiently. In May 2011, the number of monthly unique visitors to Google surpassed one billion for the first time. In May 2012, Google acquired Motorola Mobility for $12.5 billion, in its largest acquisition to date. This purchase was made in part to help Google gain Motorola's considerable patent portfolio on mobile phones and wireless technologies, to help protect Google in its ongoing patent disputes with other companies, mainly Apple and Microsoft, and to allow it to continue to freely offer Android. 2012 onward In June 2013, Google acquired Waze, a $966 million deal. While Waze would remain an independent entity, its social features, such as its crowdsourced location platform, were reportedly valuable integrations between Waze and Google Maps, Google's own mapping service. Google announced the launch of a new company, called Calico, on September 19, 2013, to be led by Apple Inc. chairman Arthur Levinson. In the official public statement, Page explained that the "health and well-being" company would focus on "the challenge of ageing and associated diseases". On January 26, 2014, Google announced it had agreed to acquire DeepMind Technologies, a privately held artificial intelligence company from London. Technology news website Recode reported that the company was purchased for $400 million, yet the source of the information was not disclosed. A Google spokesperson declined to comment on the price. The purchase of DeepMind aids in Google's recent growth in the artificial intelligence and robotics community. According to Interbrand's annual