Comment by tombert

I actually think copyrights could have the exact timeline that patents do right now and I'd be more or less happy; twenty years with a possible ten year extension seems pretty fair to me.

That's enough time to realistically make money off your creation, but not so much time that your great grandkids are also making money off of it.

The fact that a lot of things are invented and patented in the US shows that the comparatively shorter timespan doesn't appear to be discouraging innovation and creativity, and I think that would hold with copyright as well.