Microsoft filed its annual Form 10-K with the Securities and Exchange Commission (SEC) today, revealing that the Microsoft Surface lineup has garnered only $853 million in revenue for the company, which is less than the recent $900 million writedown the company took for the Surface RT. And as GeekWire notes, it's also less than the "$898 million increase in advertising costs associated primarily with Windows 8 and Surface.” The numbers account for all Surfaces sold from the device's original fall launch until the end of Microsoft's fiscal year on June 30. While Microsoft did not reveal how many Surface units it sold, Geek
