"Call of Duty: Black Ops II," the latest installment in Activision Blizzard's best-selling video-game franchise, topped $1 billion in retail sales within its first 15 days of release. The sales figure, which relies on Chart-Track retail data, means "Call of Duty" reached $1 billion faster than the movie "Avatar," the record holder for feature films, Activision said. The previous installment in the series accomplished that same feat last year. It took 16 days to reach the $1 billion milestone, compared with 17 for "Avatar," which came out in 2009.