I think that the core purpose of Advertising is "to make people know" doesn't matter what this ads tell you or let you know isn't important to them. Just the fact that you know them that they exist is what they want. if you're not thinking about it thoroughly and you often are not when you're
watching television or reading, you'll pretty much accept any
suggestion that is being offered to you. Since you're being so passive, you
may not realize it. Say you're a social climber type of person going friends with the rich ones hanging out clubbing every night because this certain bar have this pretty ads that say "70% discount on beers this Friday" because your friends want you to join them. Then boom!, every week your wallet is empty.
But its not always bad. Ads can help us to understand our society better. They show us what
sorts of ambitions people have because they show us what our society
thinks people's lives should be like. What if there is an event and you are interested in, but you didn't know it
was going to be in town because they didn't put up an Ads for that. Maybe there is a sale or a special event at your
favorite store or food shop. Advertising helps people meet their desires by giving them idea on sometimes events that is important to that
person.