I believe Amazon and other big tech companies have a business deal.
I went to the Amazon online bookstore once to browse for books that teach the basics of Cryptocurrencies. Spent about 15 minutes browsing and decided not to buy any yet. I added a few to my cart for possible future purchase.
Lo and behold, when I went to Facebook and Instagram he a few days later, I was suddenly bombarded with ads regarding cryptocurrencies!!
From Coinbase exchanges to online crypto and blockchain courses, Facebook seems to KNOW that I had expressed interest in the product simply through my browsing at Amazon!!
We are being tracked folks.
One tactic I use is the old “garbage in - garbage out” phenomenon. I have a small javascript program that performs randomized searches on google, runs in the background for a few hours every day. You can do the same thing on Amazon, Youtube, and any other major tech site.