As per the Research & Analysis division of analyst firm Forecasting and Analyzing Digital Entertainment (FADE), estimated revenues for Steam, Valve's PC distribution platform, were estimated at $970 million USD in 2010, with December capping off the year with an estimated $213 million USD. Valve was the 3rd largest publisher on Steam, bringing in an estimated $80 million USD in revenues, mostly from its 2009 release Left 4 Dead 2. The Call of Duty franchise saw great sales on the PC platform, with Call of Duty: Black Ops and Call of Duty: Modern Warfare 2 taking 1st and 2nd place in terms of gross revenues, respectively. During just 2 months on the market, Black Ops sold an estimated 1.6 million copies for just under $100 million USD. Due to the popularity of the titles and expansion packs, Activision was the #1 publisher on Steam in 2010, selling an estimated $153 million USD of content during the year.