You open a free app to do one simple thing. Before you even start, a full-screen message asks whether you want to try the paid version. The “Start free trial” button is large, bright and hard to miss. The option to keep using the free version is smaller, buried at the bottom. The same prompt appears again tomorrow. And the day after that.
A lot of people look at screens like that and think, “Surely this has to be illegal.” We even have a name for them, “dark patterns.” They feel pushy. They waste time. They seem designed to wear you down. But in most cases, they are perfectly lawful.
