Nudges in choice architecture and marketing are used to influence people's decisions indirectly through suggestion and reinforcement.
They're libertarian paternalist. Libertarian in the sense that they don't reduce people's ability to choose - the people still decide what they do eventually. And Paternalist in the sense that somebody else decides which options are going to be encouraged. For example, landing pages that have Sign up in large font and centralized, but the cancel option in small font and beneath.
This nudge approach works because it is easier and more effective to change the environment in which a decision is made than it is to change the person.
The tendency to do something and how effective a person will be depends on the environment built around it. This is why people often have the problem of chopping and changing systems in search of what works when what is needed is the right environment to make the intended target possible.
As defined by Edward Glaeser in Triumph of the City, The Edifice error is the misconception that more buildings in cities will lead to success. “Build and they will come” is the premise of urban planning that prioritizes new buildings to draw people in.