The SEC filing opens a treasure chest of data about the social network company — including the size of its financial losses. Last year Twitter lost $79.4M, an improvement from the $128.3M loss in 2011, on revenues of $316.9M, +198.1%. In the first half of 2013 the loss increased 41% to $69.3M vs the same period in 2012, on revenues of $253.6M, +107.3%. The company’s top execs were well paid by ordinary standards — but not compared to top media and tech moguls. CEO Richard Costolo’s 2012 package came to $11.5M ($200,000 salary, $8.4M stock awards, and $2.9M option awards). That’s roughly equivalent to what TiVo CEO Tom Rogers made. When it comes to operations, Twitter says it has more than 200M monthly active users who fire off more than 500M tweets per day. “Mobile has become the primary driver of our business,” the filing says. “In the three months ended June 30, 2013, 75% of our average [monthly active users] accessed Twitter from a mobile device, including mobile phones and tablets, and over 65% of our advertising revenue was generated from mobile devices. We expect that the proportion of active users on, and advertising revenue generated from, mobile devices, will continue to grow in the near term.” Investors who buy Twitter stock shouldn’t expect to make a windfall from a takeover. Directors will have staggered, three-year terms so a hostile bidder can’t unseat them all at once. Twitter also limits the ability of investors to raise issues for a shareholder vote. Currently co-founder Evan Williams owns 12% of the company, followed by Benchmark Capital’s Peter Fenton with 6.7%, and co-founder Jack Dorsey with 4.9%. Twitter hopes to trade under the stock symbol “TWTR.”