Xbox Live Marketplace has generated $180 million in revenue in the past 12 months, according to this Gama piece.
“Right now we have over 12 million users in over 26 countries, with $240 million in transactions revenue so far, with $180 million in the last 12 months alone,” said Microsoft’s IEB manager Kevin Salcedo.
Salcedo also said, interestingly, that XBLM DLC helps to stop users selling games.
“On average, titles that have downloadable content on XBL marketplace have seen a 16 percent [longer] period of people holding onto that title, which keeps them from selling to secondhand stores,” he added.
Loads of good stuff through the link.