Not happy with a Columbia University study that found that people who download music illegally buy more music than other consumers, the RIAA hired NPD Group to counter these findings.

The NPD Group found that while people who share music files do tend to buy more music than others, it is not safe to conclude that illegal downloading leads to music sales. The RIAA explains on its blog: “Some commentary has misleadingly reported that people who use P2P services like BitTorrent buy more music than non-users, implying that there’s some sort of causation.  In reality, the comparison is unfair – what it’s comparing is people who are interested in music with people who might not be interested at all.”

Here is more of the analysis from the NPD Group: “The average P2P user spent $90 per capita on music in 2004- now they spend $42 (CDs, downloads, subscriptions). This was during the same period when the number of files illegally downloaded per capita was rising.

Still, other studies and content creators argue that free content leads to an increase in digital sales. What do you think? (Via Torrent Freak).