Amazon Ads

From Podean

Early on [2012], Amazon executives realized that they were sitting on incredibly valuable online real estate (in the form of data collection and customer accessibility) that they knew they could monetize, but they had to be careful not to negatively impact the customer experience in the process.

We can think of this ads as a complementary product to Amazon's electronic marketplace or a demand-side economy of scope: once Amazon had the online marketplace, targeted ads were a logical add-on.