Kojima Productions has announced the total sales numbers of the Metal Gear series. Since the original game launched 25 years ago, the games have sold a total of over 31.100.000 copies, as of December 31, 2011.
Kojima Productions announced this number in a post on their official website about the Smithsonian Art of Video Games Exhibition that starts today. At this exhibition Metal Gear Solid and Metal Gear Solid 2 will be displayed, and Hideo Kojima himself just arrived in Washington DC to participate in a public conversation about his games. This year also marks the 25th Anniversary of the series, and with multiple releases it is an important year for the series.
Source: Kojima Productions Japan