The Halo franchise is up to 46 million games sold worldwide. Microsoft gave us the impressive figure today ahead of the launch of Halo 4, which was recently revealed as comfortably Microsoft's most expensive game to date.According to Microsoft, Halo has so far generated $3 billion in revenue, there are 120 million pieces of user-generated content in Halo 3 to date, and 5 billion hours have been logged into Halo games via Xbox Live. We won't speculate on what all these figures may rise to following Halo 4's release next week.