NEW YORK ( TheStreet) -- Amazon ( AMZN) announced Thursday that it invested $175 million in daily deal site LivingSocial, a Groupon competitor. LivingSocial also received an additional $8 million investment from Lightspeed Venture Partners. LivingSocial said it expects to generate more than $500 million in revenue in 2011, and has more than 10 million subscribers. Shares of Amazon fell 0.9% to $174.90 in pre-market trading Friday. Blackberry-maker Research In Motion ( RIMM) said Thursday it purchased The Astonishing Tribe, an interface and design company, to help with smartphone design and development. The Astonishing Tribe has previously worked with handset makers like Samsung and Motorola ( MOT). Shares of Research In Motion were down 0.5% to $62.35 in pre-market trading Friday. Yahoo! ( YHOO) M&A chief Andrew Siegel and the company's global inititaives chief Keith Nilsson are both leaving the company, according to reports. A string of top Yahoo! executives have already departed in recent months, including U.S. head Hilary Schneider and media boss Jimmy Pitaro. The company is also rumored to be rolling out layoffs before the end of the year. Shares of Yahoo! were down 0.7% in pre-market trading Friday to $16.21. Google ( GOOG) is buying the building that houses its New York offices for around $2 billion, according to a report in the Wall Street Journal. The deal is the biggest for any single building in the U.S. this year. Shares of Google were down 0.7% in pre-market trading to $567.50. Barry Diller announced Thursday he was stepping down as CEO of online media company IAC ( IACI). Diller will be replaced by the head of the company's dating website, Match.com. IAC also bought out Liberty Media ( LPCA), one of its largest shareholders. Shares of IAC were down in pre-market trading 63 cents at $28.72. --Written by Olivia Oran in New York. >To follow the writer on Twitter, go to http://twitter.com/TheStreet_Tech. >To submit a news tip, send an email to: firstname.lastname@example.org.