They sell GTX 970s, GTX 960s and GTX 950s, so lower income, or lower spending people can get a better card than their old one.
The logic of this latest premium card is that They probably sold a stock GTX 980to a bunch of people, who wanted latest and greatest, knowing better cards would come out shortly. They got the premium dollars from those people for the weakest of the pretties. Then they came out with overclocked versions, and sold cards to many of the same people, who turned around and dumped those cards on craigslist or Ebay, along with some people who waited for the better deal of the overclock. Later we saw some water blocked cards, and again, the same process happened. Then the 980ti came out, similar process. 980ti overclocks... 980ti water cooled... With this process they maximize income and sales. While they were doing this process of scaling the power up for the top end, they were also scaling down. By only offering the 980 and 970 at first, they got many people to spend a bit more for a higher end card than if they released the 960 and 950 versions at the same time. They got the maximum amount of money from their customers, and then they offered a lesser cost version which got more people to jump in and buy a card. Then again, they release yet a lower end card, but one that is better than the older cards to get even more customers to jump in and spend.