Overheard one year at GenCon:Posted by Elendur at the WotC boards (A conversation between Dave Arneson and Bob Bledsaw of Judges Guild):
Originally, Bob asked Dave if he could publish campaign setting information and adventures, and he said sure, because he didn't think anyone would buy modules! And at the time people thought it was impossible to copyright a game, so they freely shared. Bob even said he talked to Stan Lee and got permission to use all the art for the Conan comic for free. Basically nobody had any idea there was any money to be made in this hobby.
Another thing I learned was that wargames were in a very primitive state back then as well. I grew up with the Avalon Hill bookcase games that came out in the 70's, and assumed that D&D was developed from that sort of game, which was pretty well developed rule wise. But apparently the games in the 60's and earlier were much messier. So these wargaming groups that Gary and Dave and Bob belonged to had quite a bit of experience with modifying the rules, combining different rules sets, and coming up with custom scenarios.
Anyway, interesting stuff. I would have loved to have been there when Dave was running 12 people and there as many people standing around the table just to watch.