Ads are super effective. If you have something to buy, but you don't know much about it, you will tend towards buying the thing that was advertised to you more often than not just because you are more familiar with it over other things. You might not stick with it, but being the first thing someone tries is huge.

Before their media blitz campaign, Hormel’s Spam was eaten in perhaps 20% of households; after the campaign it was closer to 70%.

Ads do work, if you do them right. People go for what they’ve heard of over what they haven’t.

Repetition brings familiarity and familiarity leads to trust for the vast majority of humans. It is the reason that campaign signs works, why brand names are so valuable, and why popularity tends to increase exponentially when it works.

Most ads are just intended to get you to remember the thing they are selling.