I'd say less than 5 years. I'm not sure its even the relevant question. What length of time does a film studio, or book publisher look at for payback? If eve

I'd say less than 5 years. I'm not sure its even the relevant question. What length of time does a film studio, or book publisher look at for payback? If everyones calculating their return on the first 12 months, setting copyright to 12 months obviously isn't going to impact any industry investment decisions.