Viacom's additional $208.7 million payment to Harmonix, on top of the initial $175 million, is quite extraordinary. That's a pretty sweet deal for Alex Rigopulos et al (not that they don't deserve it. And it's definitely a sign that MTV expects big things out of the developer beyond a long life for "Rock Band." But others have covered this issue pretty well, especially Newsweek's Level Up, so I'll direct you to them for a more thorough analysis.

However as I was researching Viacom's 10-K (its annual report to the SEC) to check the numbers myself, I noticed this interesting statement: "Harmonix’s latest game is Rock Band, which as of December 31, 2007 had sold over 1.1 million bundles since its launch on November 20, 2007." That struck me as curious, since I remembered something different when I covered Electronic Arts earnings in late January. So I checked EA's latest earnings report and sure enough: "The critically-acclaimed Rock Band had a strong North American launch on the Xbox 360, PLAYSTATION3 and PlayStation 2 -- selling 1.5 million copies."

I suspect there's a simple explanation behind this, since neither of these companies would be crazy enough to dissemble in a public statement and open themselves up to liability from angry shareholders (especially EA, since I don't think Viacom would be purposefully understating "Rock Band" sales.)

Still, 400,000 is a big difference. Which leaves us all wondering... just how many units did "Rock Band" really sell last year?