
Intuitively there is an impact
Despite bigweeal's post being a minority opinion, it is correct. Nobody can be intellectually honest and believe that unfettered copying of media, games, music, etc. doesn't affect the sales. No way is it the 1-to-1 sale loss that software/media people claim...that's retarded. But it isn't zero, either.
Autodesk doesn't loose $7,000 when some high schooler copies Maya. But some percentage of high schoolers would have purchased a CD or rented a movie had the copy not been available.
We can talk about "how big of an impact", but to say "there isn't any" puts you in the same lying sack-o-#### camp as the media weasels.