Sophisticated advertisers like Coca-Cola are aware of the concept about incremental ROAS. They can't do the exact A/B test scenario of isolated consumers you're talking about but decades ago, they did do A/B tests in different tv markets where one city had more ads than another and the city with more ads had higher sales. (What the industry jargon calls "lift" from advertising exposure.)

So even brands that are already very well-known by most of the public still constantly do A/B tests to measure incremental conversions in all media including digital, magazines, sports sponsorships, etc. Back in the late 1990s, many advertisers noticed that running banner ads on Yahoo didn't work which contributed to their stock price crashing. Recently, a lot of advertisers (e.g. Proctor & Gamble) quit spending ad dollars on 2nd and 3rd-tier ad exchanges because their A/B measurements showed they were a waste of money. (The "1st-tier" ad exchange examples would be Google & Facebook.)

Can you share a link? I work in digital marketing and would be super interested in more info on this.

The benefits of brainwashing can pay dividend over a lifetime.

The product is successful not because of advertising, because it is actually good. I find it weird that, most people spend huge on advertising, but sometimes neglect the product.

It reminds of car ads. Apparently (correct me if I’m wrong), but OEM ads aren’t about converting new customers, but they’re about trying to convert recent buyers into lifetime buyers. It’s to build in the consumer the attitude of “we’re a Ford household”, not to convince a Chevy driver to buy Ford for the first time.

It’s not just that Volvo wants me to think I drive a safe wagon that is a sensible choice for middle-class, educated people who watch public television.

I want my neighbours to think these things about me even though they drive Ford and GM. That advertising assures me I’ll get both a car and a cachet.

If Volvo had a way of only selling to people who want Volvo cars for the utility, but few others would have heard of the brand, it would have less value.

It is the only path I've seen that can account for all the noise in the measurement ecosystem. And even then it is far from easy to do "right."

The future? No, statistical analysis was always at the core of advertising, from the moment statistics was invented.

It's only recently in the last few years that people forgot this, and only because techies and programmers without statistics knowledge successfully "disrupted" the advertising industry.

But internet advertising sucks balls compared to classical advertising forms, especially from the point of view of ROI to the client.

So we will eventually "undisrupt" this mess and make internet advertising more like the classical forms.

t. working in ad tech for the last 17 years.

Disagree on traditional vs digital though. It is totally circumstantial which performs better.

I’ve tried lots of colas. I’m never buying a Pepsi if there is Coke. I will always buy soft drinks in this order: Cherry Coke, Cherry Dr Pepper, Dr Pepper, Coke, maybe I’ll just have water. At this point no amount of advertising will change my mind.

“I have such strongly held opinions about my favorite soda! No amount of advertising will change my mind. I am immune to advertising!”

And then they go to the grocery store, and remember their girlfriend told them to pick up some fabric softener, which they know nothing about. So they look on the shelf and they think “Ok, Downy, I’ve heard of that one. It’s probably fine.” And away they go.

And the next time they need fabric softener, they reach for it again, because it worked fine last time, and what’s the point in spending any more time thinking about fabric softener?

This is what brand awareness advertising is meant for. It’s meant to change your weakly held preferences, not your strongly held ones.

Imagine further that this isn't a product category that you feel quite so strongly about (most people don't have a 4-deep ordered list of brand preferences for common product categories). If you were making a quick choice between Sprite and 7-up (again, for a party), are you sure that advertising couldn't possibly influence which of the brands is most accessible to your brain?

If Coke switched off their advertising they would have gained this market share in recent years?

https://www.statista.com/statistics/225464/market-share-of-l...

I don't want to be offending but this is honestly a very basic point, of course one would only measure the Return On Ad Spend from the user's acquired by said ad and not any others... Advertisers are familiar with all such basic statistics and Google/FB ads give you very easy tools to track any person who clicks on an ad throughout their entire journey.

Edit: I was mistaken as described in the comments below

Imagine a product, let's call it Oxygen, that every single person buys $10 worth of every month. It has 100% market penetration.

One day, Oxygen Corp decides to take out a $1M ad buy. They reach 1 million people, all of whom then go on to buy $10 of Oxygen, as measured by cross-site conversion tracking. $1M ad buy to move $10M of product - that's a whopping 10.0 ROAS. Must be the most effective ad campaign ever run, right?

From a gut feeling I can say that the customer came from some result of previous advertising (as we're talking about products like sodas not life-essentials like oxygen), but I guess there's no way to know since those previous ads being tv/print ads were not tracked.

If we suddenly stopped all other forms of advertising and only used online ads, in 10-20 years each customer can be tracked exactly to what ad created the first impression about the brand and thus be more accurate (still excepting marketing like word of mouth though)

You can't measure it across multiple advertising platforms very effectively though.

As you said yourself, b) breaks down for multiple platforms. It also breaks down if users have disabled tracking.

They are essentially what one needs to measure incremental ROAS of one's advertising.

Now, there are obvious caveats (online, tracking etc) but they're much much better than what's available for other platforms.

Almost all users who disable tracking also block ads, so you are still correctly measuring the effect of your ad spend.

PS: Of course that works if the difference is indeed small enough in your case so that it CAN be ignored.