what are three advantage of advertising?

I can't think of anything.

Suppose you owned a new company with a superior product no one ever heard of your product and you needed to help customers learn about its advantages. Or suppose you had to get rid of a lot of unsold goods to make room for new inventory. Or suppose you had just expanded with a store in a new neighborhood and spent a lot of money on a store opening. If you can't think of some reasons to use advertise in these situations, you should not be studying business.