I've always found the claim that Sega sold 40 million Genesis/MD systems to be a bit ... odd. 

Granted I'm going off memory, but I strongly recall the number Sega gave at the end of the Genesis/SNES generation was that Genesis sold 30-33 million or so total. Somehow that turned into 40 million over the years. 

Well this cites shipment figures directly from Sega (and Nintendo) per Famitsu magazine and one other source:

So Sega was at 28.5 million at the end of March 1996. Nintendo was at 42.30 million. I find it it implausible that the Genesis sold another 12+ million between March 1996-1998 or whatever. No way. The SNES only shipped another 6 million or so after and the Genesis was even older and losing momentum quicker. 

33 milllion always sounded correct to me, not sure what Sega is using today to claim 40 mill (classic system re-releases?). 

Where'd you hear that? I thought the excepted numbers were 32 for Genesis and 49 for Super Nintendo

They claim 40 million? I always thought people said it was in the low 30's.

No, some people claim 40 for Genesis, this one claims even higher, lol

http://vgsales.wikia.com/wiki/Fourth_generation_of_video_games

30-33 was always the number I remember hearing in the late 90s/early 2000s, then at some point some people starting insisting on 40 million, I recall one poster here snapped at me insisting Genesis sold 40 million. Seems highly implausible IMO.

Well, afaik the Megadrive still sells in Brazil, so maybe that's where the difference comes from. 7-10M Consoles in 25 years in a country like Brazil ain't impossible, especially since it's basically all they had (along the good old Master System) for many years which didn't cost an arm and a leg due to import taxes.

Wikipedia says around 35.25M.

I know you say that some people still claim 40M but I've always heard somewhere in the 30M range. Even if they were counting Brazil, the Master System was more popular than the Megadrive in Brazil and South America as a whole. Hell, they still buy that thing over there.

Nice investigation. It might not be critical today, but let's not let revisionists change history.

Interesting chart, wasn't much of a rivalry worldwide between SNES and Genesis. Would love to see the U.S. figures, I would imagine Genesis was more of a threat during that time state side.

Easy way to find out. Get someone who lives in Brazil to verify if they are still selling units.
..So I nagged DonFerrari. :P