Most, if not all the copies of software on coverdisks are older versions of software meant as a teaser for people to buy the latest versions, which manages to help sales. Those who are satisfied with the older coverdisk versions most likely weren't serious enough or didn't like the software enough to pay for it anyway. It's just silly to think that every single download is a lost sale.
Think about the whole point behind putting software on coverdisks in the first place. You received a payment and you got exposure. I've purchased quite a bit of software which I originally saw in coverdisk form. Sounds like you're now trying to bite one of the hands that feeds you.
