Publishers and developers are discovering that game demos on consoles can have a negative effect on game sales, according to newly released data.
Game designer Jesse Schell made the revelation during an industry keynote at the Gamelab conference in Barcelona on Friday, where he presented information gathered by analytics firm EEDAR.
The presentation slide suggests that the average Xbox 360 game that is promoted by a release trailer, but has no demo, on average sells about 525,000 units after six months.
But the average Xbox 360 game that carries both a demo and trailer will sell about 250,000 units in the same period.
A game with neither, meanwhile, on average sells less than 100,000 units.
The major caveat to the data is the unanswered question of whether game demos actively discourage sales, or if the best-selling games don't carry demos in the first place. Call of Duty game demos, for instance, are issued several months after the full retail game release.
Another limitation on the data is that it only examines Xbox 360 games.
In February, Schell gave an presentation at DICE 2013 claimed that games which sell the most are ones that build an expectation in players, that people wanted to try, but that didn't offer them the opportunity to do so through a demo.
"You mean we spent all this money making a demo and getting it out there, and it cut our sales in half? Yes, that's exactly what happened to you," he said.
Image: Oscar Clarke