Microsoft proudly announced today that Halo 3 has made more than 300 million US Dollars in revenues in the first week after its launch, with more than half of that number being achieved within the first 24 hours.

That worldwide sales figure included all advance orders that were shipped on day one. Microsoft's claim that the game took in "more than $300 million (US Dollars) in revenues" roughly hints at sales of between four and five million copies in the first week, depending on the price of the game in different countries. Amazon.com, for example, charges $59 for Halo 3, while German Amazon.de charges 65 Euros (roughly $90), and Amazon.co.uk charges £40 (around $80). Microsoft also claims that Halo 3 is the "fastest selling game" ever in the entertainment industry.

According to Microsoft, more than 2.7 million gamers have played Halo 3 via Xbox Live in the first week, with an average online playing time of nearly 15 hours per person in that first week.

Not only was Halo 3 a major event for gamers, it was also a major event for entertainment companies. It’s changing the way other industries look at video games. Halo 3 sparked high-profile co-marketing agreements with Mountain Dew, Burger King and 7-Eleven, among others. Most of all, it’s further evidence of the overall size of the global gaming industry. Gamers are a demographic that everyone wants to capture.