I thought 4.3 mil was kind of low as well, but you have to remember, the Genesis didn't really take off in sales until after Sonic 1's release.
Sonic came out in August '91, nearly 2 years after the Genesis launched. Sega started packing Sonic in during the '91 holiday season to counter the release of Nintendo's Super Mario World SNES bundle. And by the next holiday season, Sonic 2 hit stores and it was also packed in with the Genesis, and it basically remained that way for at least 2 years if I remember correctly, which is why Sonic 2 was the best selling of all the Sonic games and the best selling Genesis game overall.
If you were to include all the re-releases and SEGA compilations that include Sonic 1, then it would probably have nearly doubled the sales of its original release by now.
On 2/24/13, MB1025 said:
You know I was always wondering why no one ever used the dollar sign for $ony, but then I realized they have no money so it would be pointless.
