* Some of these platforms have cheaper tiers that are ad-supported.

* All of these platforms favor algorithmic recommendations (which are ads) over your personal content queue.

* A lot of content on Prime forces you to watch an ad of new Prime content before your show starts.

* Some of these platforms have auto-playing previews that distract you while you are navigating. Sometimes you can disable them, sometimes you can't. Sometimes the setting resets itself. These are ads.