Amazon Knows What You Buy. And It’s Building a Big Ad Business From It.

When a chain of physical therapy centers wanted new patients, it aimed online ads at people near its offices who had bought knee braces recently on Amazon. When a financial services provider wanted to promote its retirement advisory business, it directed ads to people in their 40s and 50s who had recently ordered a personal finance book from Amazon. And when a major credit card company wanted new customers, it targeted people who used cards from other banks on the retail site.
Read more: https://www.nytimes.com/2019/01/20/technology/amazon-ads-advertising.html?source=Snapzu