The trick isn't figuring out whether advertising in general influences people's behavior. The trick is in figuring out if any particular advertising campaign generated more profit than it cost to run.
Also, there's one alternative that's often forgotten in these discussions: Perhaps game theory is at play. It may be, for example, that, across entire industries, advertising costs more money than it's worth. But that everyone has to do it anyway, because anyone who chooses not to will start losing ground to everyone else. IOW, just like in the standard prisoner's dilemma, choosing to act is less about increasing your potential gains than it is about limiting your potential losses.
There is an interesting long-running natural experiment in the pharmaceutical industry that suggests, albeit inconclusively, that this is the case.
Distilling it down into "any particular advertising campaign" is pretty myopic in this world. It's about strategy as a whole over decades. Not every ad campaign is to drive immediate sales or signups (direct response). Branding and awareness campaigns can take years to run, and these are ALL diligently measured at every stage. Losses do occur do to negligence, malice, and poor execution all the time, but the brands should take some blame as well as they often feel compelled to spend. They have huge budgets that they NEED to spend regardless of they perform - sometimes due to accounting shenanigans, sometimes because they don't know any better, etc.
No matter what time scale you pick, there's still a point where ad spending costs more than you benefit. As time passes, the boost from any campaign decays. For any particular person you only need to show them so many ads to maintain awareness.
> these are ALL diligently measured at every stage
Mmm. Sometimes. Sure, you can obsessively measure audience and sales numbers, but if you don't have any controls then it becomes nearly impossible to figure out how much of that came from ads and how much came from everything else in the entire world.
it is true that that profit/loss point exists, but it may be impossible to measure. But it's very clear that 75+ years of Coca Cola marketing strategy has produced the situation where any human on earth immediately associates "Coca Cola" with soft drink.
If Coca Cola cut advertising 90% this afternoon, they likely wouldn't see the consequences until a new generation or two grew up.
I suspect that a similar dynamic can be in effect with many industry events. Everyone would collectively perhaps be better off with pulling out of or at least scaling back on big industry shows. But that doesn't mean it makes sense for just you to pull out. (And, certainly, your events team probably isn't going to push for scaling back.)
There's also a huge mutual back-scatching thing going on. I remember in a former life we wanted to pass on a big software vendor's user group show because, while we sort of needed their software for some important customers, we got very little traffic at this expensive event. Their CEO called our CEO and basically said to him "Be a pity if something happened to our partnership."
> IOW, just like in the standard prisoner's dilemma, choosing to act is less about increasing your potential gains than it is about limiting your potential losses.
You seem to be assuming that the potential gains are limited to current players of the game in this comparison.
It's possible that Coke, Pepsi etc. are all losing more money on ads than they're gaining in market share against their current competitors and in increased sales. But that doesn't begin to address the question of whether advertising is a net loss.
For one, the advertising also serves as a collective moat against new competitors, which could enter the market and eat up both Coke and Pepsi's market share. Maybe their biggest gain from it is that a bankrupt soda company from the 80s didn't replace them, and that a similar company today wouldn't have room to enter the market.
It also doesn't account for more complex effects like a net increase in sales for all companies in that market. E.g. maybe Rolex, TAG Heuer etc. all benefit in the long term from expensive watches being seen as fashion accessories.
If Rolex stopped their advertising spend one month and saw little immediate change, then TAG Heuer etc. might follow suit. But both might only experience the real loss years later as "luxury watches = must buy" faded from the psyche of their current and potential customers.
Also, there's one alternative that's often forgotten in these discussions: Perhaps game theory is at play. It may be, for example, that, across entire industries, advertising costs more money than it's worth. But that everyone has to do it anyway, because anyone who chooses not to will start losing ground to everyone else. IOW, just like in the standard prisoner's dilemma, choosing to act is less about increasing your potential gains than it is about limiting your potential losses.
There is an interesting long-running natural experiment in the pharmaceutical industry that suggests, albeit inconclusively, that this is the case.