If Sonic Rush is any indication, Sonic is actually strongest in "others" territories nowadays. So nearly 90K in Feb for Secret Rings might not be so bad. It could work its way to 300 or 400K from there. The game seems to still be popping up in top 5 Wii sales lists for some PAL territories, too, though there's no indication of sales there. Of course it was just a few years ago that many different 3D Sonic games were pulling 2 mil + on multiple systems... Sonic Adventure on DC, Sonic Adventure 2 on GC, Sonic Heroes on PS2... Now 1 million isn't in the bag for any Sonic title... Ouch...
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.