Absolutely...you have kinda nailed it here with both comments.
My best "customers" were actually people who had a good deal of "income" (remember...there are many millionaires in prisons all over the world) who really didn't mind losing $1 a game 1. to get better and 2. for a safe social interaction with someone like myself who has a sparkling wit and overall interesting things to say (so I've heard :)
Prison isn't really that much different then life, but the sociopaths you meet there are far more likely to be violent then the ones running your company.
If folks are sufficiently hard up for entertainment that they're willing to pay a dollar (more than you'd think, in prison) for a game of chess, they're gonna value that game and its provider.