The Core

QuoteTo see the A/B tests running on any given website you visit, you can download a Chrome browser extension called Pessimizely that will reveal everything that Optimizely is facilitating, from advertisers experimenting with which ads to show you to the New York Times testing out different headlines.

A/B testing rules the web. That could be a serious problem
https://www.fastcompany.com/90306916/were-all-being-manipulated-by-a-b-testing-all-the-time