We're theproduct...
The point of a "smart fridge" is that we're not the customer, we're the product. The fridge would identify that we have run out of our Amazon supplied, bland, over-priced, generic cheddar and send us some more. It'd remove the option ( and the will) to shop around or try a new product - unless it was one they were promoting to increase their profit margins. If they had their way our branded, Amazon supplied SmartFridge would have fixed slots for a range of standardised items. ( A bit like those hotel mini-bars with every item in it's own sensor checked slot, that try to charge you if you move their over-priced booze out of the way so that you can bung in a carton of milk ).
This would tie us in to their retail outlet, selling us a smaller range of standardised products and charging us without us even knowing what we're buying and how much it costs us. We'd just pay our bill at the end of the month, probably automatically.