There's a great little initiative that has been implemented on RPGNow, and I've just jumped on the bandwagon with a few products.
It's called "Pay What You Want", and it allows a customer to determine their own level of pricing for a product. If they want it free, they can set the price to zero...if they think's it great and want to support the author, they can offer a few dollars (or more).
I think this is great, especially in a world of PDF publishing, where someone could download a product then put it up on a torrent site (stripping out any protection data if they had the right skill set, or just a decent printer and scanner).
I've started by implementing this concept on the core rule sets for FUBAR, and the "Games for Goblins" booklet. I've been giving these games away for free anyway, but it would be nice to see if people think they're worth a bit of money.
We'll see how this initiative works over the next couple of months, and I'll report back my findings at the end of the year.