Myst required a CD ROM drive — one of the earliest games to do so. This when optical drives were new, add-on devices that few people had.

This should have been an obstacle to the game's success but lesson learned: it seems that everyone that had a CD ROM drive bought the game.

I'll never to fall for the least-common-denominator school of marketing. Ship your games and require the most high-end of hardware. :-)

Oh, and it helps if your game is great (and the game's size no doubt helped reduce piracy).