I think it is a ploy to have people sign up for Prime (reminds me of the cellular industry many years ago when they first started to offer free minutes and text, it got you hooked on using it).
Hint: If you are looking for the latest GoPro find someone who is attending a photo/video/electronics convention trade show (WPPI, NAB, CES, etc..) where they have a booth, they always have codes for a very nice discount, you have to pay sales tax in California for buying straight from them but it's still the best deal.
-MW