Halo 3 Sales Top $300 Million In First Week; With more than $300 million in sales in its first week on the market, "Halo 3 is truly a cultural phenomenon," says Microsoft chairman Bill Gates.

Halo 3, for Microsoft's Xbox 360 platform, went on sale Sept. 25. With first day sales of $170 million, the game has already broken a number of industry records for market performance. Retailers took more than 1.7 million pre-orders for Halo 3, another record.

The game is also setting new standards for online play. More than 2.7 million gamers played Halo 3 over Xbox Live in the first week, according to Microsoft.