"Ad buyers don't care if it's effective." Yes, they definitely do.

Some do.

Others spend a million dollars a month on whatever stupid idea a team of Account Managers in $6000 suits/outfits with $500 haircuts pitch to them. And then congratulate themselves when the Analytics Department produces graphs of whatever meaningless metrics they can find or make up that go "up and to the right" for each month. And the Regional Ad Buyer and the Digital Agency will convince themselves that attributing every single sale to that advertising spend is valid and acceptable accounting practice, when most of the client's product practically sells itself. And they'll do this for a decade or more, until Global Head Office notice, then they'll pull the plug with 3 or 4 months outstanding unpaid, leading to ~100 people getting laid off with zero notice and tens of thousands of dollars of unpaid monthly salary and entitlements.

At least, that's how it happened last time I got burnt by it...

This isn't the 1900s. You can measure how well an ad performs and how well it converts into a sale.

You can.

Some people do.

The rest of my post stands.

That in itself requires clarification. There have been years in which Facebook is caught lying about as metrics in all 12 months.

Do ad agencies care if x number of units sell, or do they care that a report cause the commission check to clear? I say the latter, more typically.

Then why are Internet ads so terrible? Ever more annoying ways to present ads might make people accidentally click on an ad, but seem like a bad way of getting people to buy the product. Even video ads are generally terrible, many of them fail to even tell me the name of the thing I am supposed to buy before that 'Skip'-timer has run out.

The Internet would offer so many different and better ways to keep consumers informative about new products.