Doom, one of the most influential videogames of all time, was famously distributed via the shareware model: The game's first chapter was completely free, and if you liked it, you sent id Software some money and they mailed you the remaining two episodes.
What would sometimes happen in those pre-online days, though, is that less-than-scrupulous resellers would offer the shareware version for sale, even though it was meant to be free. For $5 (or whatever, it's been a while), you could take home the hot new shooter from the guys who made Wolfenstein—and sure, you weren't getting the whole thing, but whatever. It's still Doom. Do you want to play it or not?
