Therapeutic suggestive therapy through hypnosis is something you come and ask for because it can greatly help you achieve your personal and medical goals. In the office it is direct and overt.
Sometimes when i work with a client they bring their partner and the partner may listen with their eyes closed and also go into trance. This is mostly because they want to know what its like so they also follow my instructions.
Because hypnosis has such a wide interpretation I guess you could say that the repeated suggestion of marketing surrounding you is a form of hypnosis and that may be something you consider against your will. You pass by a billboard with food on it and suddenly you realize that you're getting more and more hungry.
Hypnosis is about bringing about a state with heightened suggestibility. This happens often very naturally for instance when someone falls and injures themselves them may go into shock. Imagine a baby falls down and is shocked and looks to their parents for how to feel and what to do. If you get upset they will take your lead and cry scared and likewise if you smile and say "you're ok, here let me kiss it and make it better" they take that suggestion and feel better. That is an example of hypnosis. Was it against the baby's will? No. It was a suggestion the baby was happy to accept because it was what they wanted to hear, a confident parent providing positive suggestion in a time of need.