LivingSocial, the daily deals giant, more than doubled its revenue in 2012, but still reported a net loss of $650 million, according to a new regulatory filing by minority owner Amazon. The net loss, up from a loss of $499 million in 2011, included a $579 million impairment charge. The news comes two months after LivingSocial cut approximately 400 U.S. jobs, or about 9% of its workforce, primarily in sales. Amazon invested $175 million in LivingSocial in 2010, and currently owns a 29% stake in the company. As of Dec. 31, the book value of the investment was $52 million. Read more.