I like the idea, but what would be the advantage of using it over Amazon? Amazon has a robust database of products, a well entrenched and fairly accurate review

I like the idea, but what would be the advantage of using it over Amazon? Amazon has a robust database of products, a well entrenched and fairly accurate review system, and all the product specs given by the creator. You also have the option of buying it on the spot. I think this sort of idea would work best for a type of product that, unlike consumer electronics, would not be readily available on Amazon. Maybe something like cars?