What tricks will companies use to get your money?

Supermarkets place the essential items the furthest from the entrance ensuring you walk past everything else to get there and maximizing your chances of buying other shit you don't really need. Instagram and other social media platforms have done extensive tests on which layouts, colors, sounds, images, and so forth maximize time for a user to spend on the platform.

These are some of the more obvious and well known ones. What are some lesser known and more subtle marketing tricks?