also one should always be skeptical about the extent they believe they are not influenced by ads. that runs pretty deep. you say you instinctively don't trust it. but when the time comes to buy something, you won't automatically steer yourself towards a product that you have never heard before just because you have not seen an ad for it. having some names in your mind, even them showing up when you do research creates influence.
Such a belief purports that the effect of all advertising is measurable. It clearly is not. For example, someone sees your ad and decides your company is reprehensible. They were not a customer and they decide to never interact with your company. It's not possible to measure this. Anyone claiming it is holds what amounts to a religious belief.
The "generates negative returns" is the next myth in this. Whether or not advertising generates positive returns is not relevant. You can't measure the return of advertising in the first place. Even if you could measure it, you should be comparing it to the opportunity cost of not doing something more productive with that money. Which you also can't measure. No one rationally proposes that someone spends a hundred dollars on advertising to generate $100.10 in revenue is somehow a good use of money.
It's very hard to poll or measure things to within a fraction of one percent with most audiences. But that's not what's needed for advertising. And in marketing you probably don't care about that - it's in the noise. You do care of "significant" changes and you can of course measure both positive and negative influence.
Even negative influence in people who aren't yet customers, or have never heard of your company, and (preferably) have never seen your ad. For example through a polling survey. Funny enough, such a poll is probably an effective ad campaign in itself in some cases! You can also measure opinion strength about advertising in general. It's more nuanced than you think. Which unfortunately leads marketing departments to commit atrocious injury to good taste. Agreed there.
> No one rationally proposes that someone spends a hundred dollars on advertising to generate $100.10 in revenue is somehow a good use of money.
Of course not, and yet they spend far more than that, to good (measured) effect.