That's not as bad as Criteo... The other day I visited some website, looked at a product, decided I didn't like it, and left. A half hour later I got an email

That's not as bad as Criteo... The other day I visited some website, looked at a product, decided I didn't like it, and left. A half hour later I got an email from the same site offering me 15% off of that product. I had never visited or heard of the site before. Talk about shady... Apparently Criteo can accurately identify over half of the visitors to a site.