Quote: Sony's interchangeable lens cameras and lenses have seen record sales in 2017, in particular within the U.S. full-frame camera market, where they have experienced double-digit growth (+23%) compared to the same period last year. The popularity of key models including α7RII and α7SII has been paramount to this success.
Additionally, Sony's rapid growth has helped to drive growth of the overall full-frame interchangeable lens camera market compared to the same period last year. Without Sony's contributions, the full-frame market would be facing a slight decline.
The thing here being that Nikon is not even in the position to consider closing down their failing DSLR business without closing the whole company.
Interesting anniversary year for them.