Valve Software believes its community of fans can be the best people to announce new games, a representative of the company has said.
Jason Holtman, who spearheads Valve's Steam business, explained to an audience of industry executives how the studio managed to create a frenzy of interest in Portal 2 without a single press release or advertisement.
"Portal 2 was announced by adding content to Portal 1," Holtman said.
Speaking at the Develop Conference in Brighton, Holtman proceeded to explain how tweaking content in the first Portal - such as adding mysterious radio frequencies that hinted at a sequel - triggered an internet craze.
To the untrained eye, the radio frequencies appeared to be inconsequential, but eventually the clues hidden within were extracted by eagle-eyed fans. This, in turn, generated a vast and vibrant community of people speculating the meanings behind the clues.
A single discussion thread on Valve's official forum had generated some 2.7 million views, with thousands of people involved in the discussion.
Holtman also explained that Valve updated the first Portal game with an additional few seconds of content at the end. That in turn sparked another craze, with people posting the video endings on YouTube, watched by hundreds of thousands of people.
Portal 2 was officially announced a few days after the buzz of community rumours.
Holtman said the whole initiative was "better than buying a billboard advert on the side of the Chrysler building".