In two weeks five modders from the Team Fortress 2 community made between $39,000 and $47,000 selling items through the game's new Mann Co. Store.

The royalty figures were so high they exceeded PayPal deposit restrictions, so Valve flew the highest earners - Spencer Kern and Steven Skidmore - to its door to hand the cheques over in person.

"It was completely mind-blowing, the size of the return that we're getting on these things," Kern gushed to Gamasutra.

The Mann Co. Store was added to Team Fortress 2 (PC) at the very end of September. It enables player-to-player trading and provides a storefront for modders to sell their TF2 content. Creators keep 25 per cent of the money made.

"It benefits us because it grows the community, right? These [content creators] benefit, but we benefit too," reasoned Valve brain Gabe Newell.

"Team Fortress 2 is a better product because we have community contributions in it. They're going to go off and listen to what the community says about how they can do that better, and we can draft along, as we both benefit."

Newell reckons the idea will eventually catch on: "Once people ... realise this is about their community, and that the right people are getting the benefits, ... after a while, they'll say, 'This is really how these kinds of communities need to work.'"

Team Fortress 2, a caricature-styled multiplayer shooter, was released to wide acclaim in the autumn of 2007. Three years on, the PC TF2 community is as healthy and enthusiastic as it ever was, thanks to devoted support from Valve. The same isn't true of the PS3 and Xbox 360 versions of the game, as the closed nature of Xbox Live and PlayStation Network has made it impossible for Valve to unleash the same amount of downloadable support.

Tom Bramwell reviewed Team Fortress 2 for Eurogamer.