> Doesn't "some ads work on you" just translate to "you have interests"?

That is not the meaning I give it.

Ads can do a lot of things.

A simple example is to educate/inform. There are certain things I will buy when I know that they are available (e.g., seasonal items). Ads will let me know that they are available.

Other ads can do more ephemeral things like build trust (e.g., many bank/investment type of ads).

There are other things ads can do. Ads and marketing are a well-established field, and explanations of that field can be found online fairly easily.

> Or are you suggesting the ad itself does "something" to people that wouldn't have happened if they saw the content of the ad some other way?

Not sure what you’re saying here.

I will say that ad campaigns do “something” to some people that wouldn’t have happened if they hadn’t seen the ads in the campaign (slightly different than what you wrote).

Rarely will a single ad move the needle unless it’s for a major event like the World Cup final or the Super Bowl.