PapersAndPaychecks said:
I think Henry's figures might be a bit low -- perhaps the numbers he gives could be doubled or tripled. (This is based on the distribution figures for my 1e .pdf's which are hosted on Dragonsfoot.)
I think you're both way low: the AD&D MM, PHB, and DMG were each printed and reprinted in the
millions through the height of D&D's heyday. Based on WotC's 1999 pre-3e marketing survey--which speaks to 1e/2e D&D player demographics---6% of the overall US population have ever played rpgs, while 3% play monthly. Those percetages are after at least two major rpg market crashes and the emergance of PC games as key competitors, neither of which which were factors for TSR or D&D until well-after 1986; I think those figures would be higher if TSR had performed market research back in the day.
The US population in 1980 was 226,545,805 so 6% of that figure is 13,592,748 people who ever played AD&D in its heyday (the percentage was likely higher), and 6,796,374 people who played at least monthly (again, likely higher too).
The question becomes how many players are still playing pre-3.x D&D after 1999, when the national survey was conducted? The US population in 2000 was 281,421,906, so there should have been 16,885,314 folks who'd ever played rpgs around (using the 6% figure sans caveats), and 8,442,657 active monthly+ gamers. While TSR's market share had fallen during those darkest years just before WotC bought them, they still commanded around 60% of the market, so there should have been 5,065,594 folks who had ever played D&D around, and 2,532,797 or so active gamers playing D&D at least monthly.
How many of those 2.5 million active players never converted to 3.x, or converted and switched back? That's much harder to guesstimate, and will have to wait for a night when I have a little more time on my hands than is left in this evening
