Most of Halo 4 is still under wraps, at least until the game's release on Nov. 6, but Polygon has an extremely interesting look inside the Halo 4 playtesting labs. And in the article, Phil Spencer, the head of Microsoft Studios, reveals an interesting tidbit about where Halo falls within Microsoft's larger scheme. Surprise: it's important.

In fact, Spencer said that Halo is the "most important entertainment product in the company." Microsoft's other exclusive franchises include Gears of War, Fable and Forza, but predictably, Halo trumps them all.

Even more interested was Spencer's response when asked whether Halo 4 is the most expensive game Microsoft has ever invested in: "Absolutely," he replied. "Nothing's even close."

Joystiq reports that Halo is estimated to be a $3 billion franchise. Halo 3: ODST is said to have reeled in $170 million in its first 24 hours, while Halo 3 reportedly cost $60 million (including a $30 marketing budget). That's huge, but to be fair, according to Polygon Bungie reported that Halo 3 made $300 million globally in its first week, making it "the fastest-selling video game ever" at the time.

So yeah, Halo remains a big deal. Are you looking forward to Halo 4?

[via Joystiq]