This implies you don't do any research for products other than amazon reviews and official marketing material. I think this is typical for some kinds of products, but not necessarily typical overall.
I think it's typical for most products people buy. I'll do research and compare products/vendors when I'm purchasing a TV, but if I need sponges for the kitchen I'm just going to type "sponges" on Amazon and [most likely] purchase something from the first page of results.
We all purchase a lot more sponge-like products than TV-like ones.
And if people aren't clicking "buy" through Google's ads, then that's really... not good.