Amazon I think tracks whatever it can. Whenever I visit a product, even if I didn't buy it the product (or something similar) will show up as "Continue shopping ...", and not very later as ads on my Facebook feed. It almost creeps me out (I use quite a few filters on uBlock), considering there is no visible facebook "Like" button on Amazon.

Not sure how it works, but whatever I see on Amazon shows up as ads on Facebook.