Can people be manipulated, or tricked to do things that they would, when sound of mind, otherwise choose not to do?

Let's just assume you answer "yes" (because to answer "no" would be unimaginably absurd)... lets also imagine that billions of dollars are up for grabs to the people/companies who can manipulate/trick sound of mind people better than anyone else... What would that world look like?

Well, we're living in it.