Statistically speaking, the only thing advertisers are good at selling is their own services to businesses. Advertising is a miserably bad investment that mostly just eats up funds, even as it's forced to exist by businesses needing to be seen and known about. Like nobody alive sees an ad and thinks "ah, I must own [thing] now!" they just maybe notice that [thing] exists and maybe at some point remember that it exists but are more likely to just run across it when doing a search for [general type of thing] later anyways. But without engaging in it, businesses suffocate because they never build up a critical mass of being known about.
It's all such a fucking stupid and pointless grift that has no reason at all to exist and it doesn't even do the one thing it's claiming to do well at all.