Reading this, one gets the feeling that Amazon advertise their products on some sort of public place, and that this is perhaps not right. But in reality they simply own the whole thing and it is perfectly reasonable to do however they want.
[1] https://www.cnbc.com/2019/07/17/eu-to-investigate-amazon-ove...
[2] https://www.theguardian.com/technology/2020/may/01/amazon-je...