From the Guardian:

Computer-literate music fans who illegally share tracks over the internet also spend four and a half times as much on digital music as those who do not, according to research published today.

The survey confirms what many music fans have informally insisted for some time: that downloading tracks illegally has also led them to become more enthusiastic buyers of singles and albums online.

Recent figures from the International Federation of Phonographic Industries showed that the number of legal tracks downloaded internationally tripled to 180m in the first half of the year, while the volume of tracks being traded illegally rose only 3% to 900m, despite the increased penetration of high-speed broadband lines.

In the UK more than 5.5m online tracks were sold in the second quarter of 2005, a rise of 744% on the previous year.

This can be easily applied to games as well.