I worked briefly in a marketing department as programmer. Learned the following there. The benefit of advertising is to inform the consumer of products they may not be aware of. "Messa thinks Messa might have Mesothelioma!" Most of the time advertising is a waste of time, and there certainly are better ways of learning about products. However, the function of informing consumers of products they may not be aware of is of mild benefit.

A better question than what benefit is advertising might be, "How can advertising be made more beneficial to the viewers"