Microsoft and their partners do sell millions of tablets per year, it's just that their unit sales pale in comparison to Android and iOS tablets. I'm also not even sure if Microsoft calls their Surface line tablets anymore. Their product page now calls them laptops which is odd considering you sort of need the optional keyboard to be a laptop.

>So I wonder where they are being bought from, is everyone getting them from Amazon?!

Amazon accounts for good percentage of tablets sold. I bought an Amazon Fire 8 HD for $49 during Prime Day. At that price it's an instant purchase.