New research suggests that releasing a demo before a game is released with actually damage potential sales, potentially halving the number of copies it will shift.
This was revealed by game designer Jesse Schell during the recent Gamelab conference in Barcelona, according to CVG. Schell based his claims on new data from research firm EEDAR.
According to the study, the average Xbox 360 game that is preceded by both a demo and a launch trailer will sell around 250,000 units in its first six months.
However, titles that only released a launch trailer and no demo sold more than twice as many copies – as much as 525,000 – in same period.
Any game that releases with neither a trailer nor a demo sold an average of 100,000 units.
But it should be noted that the study doesn't conclude whether or not demos discourage sales directly.
It could be that the best-selling games don't release demos because they have rarely needed to in the past: Call of Duty, for example, only releases demos months after launch.