Nvidia has been one of two primary graphical processing units manufacturers along with AMD. They have been one step ahead of AMD and recent statistics show that Nvidia is still the number one choice for gamers. AMD has always been second to Nvidia in terms of innovation however many would argue that they provide better price to performance ratios and are budget friendly from GPUs to CPUs.
In the above chart we can clearly see that AMD is nowhere to be seen and the GTX 1060 is leading all the way. The survey also suggests that Nvidia seems to be the better choice for gamers as a whole and clearly dominates over AMD. The real question here however is that even after the new VEGA architectur by AMD they are nowhere to be found.
Another thing to note is that the GTX 1070ti is not the best choice here since a person with that sort of price range would rather get a 1080 or just go for a standard 1070. The 1070ti has been the choice for 0.62% of steam users. Note that these surveys paint only half the picture. Since steam is merely a platform and the surveys by them only represent the gamers which use their service.