Advertising gets such a bashing from the world. At parties you are always asked, 'Aren't you just selling people things they don't want?'
There are rules in advertising, and those rules are self-imposed by the client companies because they don't want their products to be seen as dishonest.
We are all advertising, all of the time. If you want to sell your car, what do you do? You clean and polish it and make it the best you can. Some people bake bread when they are trying to sell their house because the smell adds a friendly feeling. Even the priest, with all his or her fervour, is advertising God. Everybody is selling.