> many PR firms exist to push your product onto media outlets

> personal recommendations

Half of that is fraud, the other half is at least unethical. Reviews may only be the personal opinion of people who provably purchased the product. False reviews are fraud and explicitly a criminal act. Placing ads in media without explicitly marking it clearly and obviously an ad, so-called “native advertising”, is explicitly a criminal act.

> the prevalence of advertising is such that you cannot disentangle its influence from every other.

My original argument was that advertising isn't necessary. I think after this discussion it's become obvious that there are many other working and prevalent ways to discover products.

In fact, all advertising does is distort and corrupt those existing methods, trying to get me to spend more money than necessary on a worse product. Every cent spent on advertising could've been spent on improving the product instead.