> Duh, just solve the fundamental problem that has plagued advertising since the birth of the industry!

That's kind of why Facebook/Google was ever supposed to be valuable: they empower the analysis. How do you do good analysis with bad inputs?

You don't really.

But assuming the FB/Google reported numbers are accurate, would you pay for them and just convince yourself they are actually increasing your sales?

You should be able to at least plot sales numbers against ad spending per week over a year.

Facebook also "should" be able to report numbers in a way that isn't misleading to their customers.

Ah, classic courtroom fraud defense. "Feel fortunate you even caught me; that would've been impossible a century ago!"

Having wiggle room on numbers isn't a bad thing. Lying about the amount of wiggle room on said numbers is.

You can do the analysis that you want, there's no proof that advertising increase something. They are bad and should be banned from our live.

See my reply to the comment above. With local retail, you can't just measure the conversion rate.

It is not about the specific number of seconds. It is about the implied engagement and focus of the audience. It is about a reported difference in the behavior of Facebook users vs other online properties.

You never can. But are you just going to blindly spend money on ads and just believe they work?

Yeah, that is basically the entire advertising industry. Precisely what "brand exposure" is.