But they are selling at a far worse pace, even with the limited 680 availablity
If you look at the steam hardware survey, 0.5% of users have a 7970, 0.56% have a 680 gtx.
While that is a small difference, factor in the fact that the 680 has been in the market for a far shorter period of time and supposedly had supply problems, it really paints a picture of who the market prefers for high end cards.
Steam survey is not a real survey, hell they just fixed some bug that had skewed all kinds of stats.
But even if real, you'd think GTX 680 outsold 7970 10-1 going by forums. What you're showing is that today they're not too far apart from having sold the same amount. That isn't bad. Then add in AMD has been selling the 7870 and 7850 and 7770 and 7750 for months with no competition, I bet AMD has upwards of 80% 28nm market share.
I like how people are proud of it though, like "yeah it's worse but we buy Nvidia anyway cus we're fanboys, isn't it awesome"
I bet at this point if AMD made a CPU faster and cheaper than Intel people would proudly flaunt how they still buy Intel, and make up some fake reason like the driver for why they buy Nvidia "I buy Intel cause their CPU drivers are so much better!"
Anyways it's Nvidia that is in trouble because they're losing overall graphics market share (hmm, you didn't mention that for some reason LOL) to AMD and Intel integrated. It's good for Nvidia they started getting into mobile because discreet GPU is becoming more and more marginalized, and Nvidia is in a bad position since they have no desktop CPU.
Anyways the problem with mobile though for Nvidia is margins are a lot lower than desktop GPU.