It might benefit you to take some marketing courses to understand why these sort of ads are effective and useful. Just because you don't understand something doesn't mean there's no rational explanation for it.
(In general, it's a good rule of thumb to assume that the widespread existence of something suggests there's a reason for it, and to be inquisitive as to what that reason might be.)
He didn't ask how these sorts of ads are effective or useful. He asked how they inform consumers, which was the point someone else previously brought up as a defense.
(In general, it's a good rule of thumb to assume that the widespread existence of something suggests there's a reason for it, and to be inquisitive as to what that reason might be.)