Re: don't worry, our ads aren't as effective as we told you
I have no idea how effective advertising is.
I do know that Unilever has groups of people measuring exactly that, and suspect other similar companies do the same.
Unilever spends billions.
I view it as a sort of 'peacock' style evolution.
If you spend nothing, you lose, if you spend, you needs to spend about the same as your competiors (certerus paribus) otherwise you lose.
So the displays slowly grow until they restrict the ability to do something more useful, like product development.