It doesn't help to blame advertising for many of the world's problems. It is more useful to understand the techniques used to change people's behavior. Advertising researchers study people's reactions to different messages. The researchers look for factors that cause people to act in a certain way. For example, in a study of how children got their parents to buy them things, researchers watched children fight with their parents. This was an opportunity to learn how to make advertising more successful.
Some techniques are used to bring particular messages to particular groups. An example of this is the suggestions we see online that promote books similar to ones we have already bought.