According to an industry keynote by game designer Jesse Schell at the Gamelab conference in Barcelona, apparently game demos tend to have a negative impact on sales rather than sparking an interest in buying full releases. This is from information gathered by the EEDAR. It stated your usual Xbox 360 game with a release trailer and no demo garners 525,000 units in a six month period, but a game that features both a demo and trailer will average about 250,000 units in that period.
And in case you’re wondering, a game that has neither manages to notch up less than 100,000 units. However, despite the revelations offered by the data, it is unsure whether game demo are actively discouraging sales. Then again, Call of Duty never has any game demos – these actually come out several months after the main game has made a killing in the market.
Schell perhaps summed it up best during his presentation at DICE 2013 when he stated that, “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.”
Source: CVG