ATT, where apple hobbled other ad networks running on iOS. It used to be that DTC companies could use the fine-grained targeting offered by FB and Google to reach consumers without needing to go through a major distributor. Since the targeting is much less effective it's more expensive (potentially uneconomically so) to reach people. As a result, sellers are forced back to Amazon.

Lots of TLAs:

ATT: Apple's App Tracking Transparency, not AT&T

FBA: Fulfillment by Amazon, not related to FB

DTC: Direct To Consumer, not Depository Trust Company

What is a TLA?

TLA = Three Letter Acronym

TIL TLA’s meaning

TIL = Today I Learned

Sorry, couldn't resist :)

and ETLA = Extended Three Letter Acronym

I work with DTC Shopify brands and I personally haven't found the ATT hurting ads performance in both Meta and Google. I'm sure YMMV but I've not seen it since it started. Maybe I work with very broad targeting compared to others.

was there also any change related to Apple wanting a cut of anything sold through an app, and how the Amazon shopping app works on iOS, and could that also affect 3rd parties?

No, physical goods have always been excluded from Apple’s commission

In fact they explicitly prohibit using in-app purchases for physical goods, presumably because they don’t want to deal with the headache that comes with providing customer support for those transactions.

Businesses got along just fine before all that intense user tracking was even possible. If your business absolutely needs it to survive, then your business doesn't deserve to survive.

"boo hoo, I can't invade my users privacy anymore! Waaaaah! It's unfair"

A lot of the old machinery for small businesses to find their customers - e.g. news, hobbyist magazines, etc - is no longer around, and so there's nothing for those businesses to return to. The Internet, and specifically advertising companies, killed them off. What's unfair is not that they can't violate privacy, but that Amazon still can.

Weren’t those outlets even less targeted?

The key was that people self-selected into those outlets. If you were selling, say, game controller skins; you'd be making a pretty sure bet buying ads in GameInformer or on Joystiq. The problem with going back to that kind of business model is that these dedicated websites with specific niche audiences are dead or dying because the ad dollars moved elsewhere.

Shouldn't the ad dollars be moving back in after super targeted advertising got neutered?

It kind of is. Look at magazines like Monocle, and websites like Uncrate, Hiconsumption, and Gearpatrol.

Is Amazon somehow exempt from the App Store's privacy rules?

Amazon has its own enormous scale, it doesn't need Apple's complicity.

For one thing, the privacy rules only cover sharing data with third parties. They don’t cover Amazon using its own data for product recommendations.

But also, Amazon doesn’t rely on product recommendations in the first place. When I want to purchase something, I usually go to amazon.com and type in exactly what I’m looking for. No need for Amazon to guess. Amazon does make recommendations, but at least in my case they represent a tiny fraction of purchases.

In that way I’m voluntarily contributing to Amazon’s monopoly. I feel bad about that. But I use Amazon anyway because there are no alternatives that offer even a remotely comparable buyer experience.

Apple limited data from being transferred between apps. So you can’t measure whether your ad being clicked in one app resulted in a purchase in another app (aka. a “conversion”). That throws a big wrench into ad pricing, because the sellers want to pay-per-conversion. It hurt companies like Snap, Shopify. Since Amazon owns both the search/discovery and checkout in the same app, this doesn’t affect them.

Also, Apple didn’t limit their own advertisers from measuring conversions. So if you click an ad in Apple News and then buy an app from the App Store they will measure and charge the advertiser for that conversion without ever popping up a scary message saying Apple wants to track you. Go figure.

The companies have worked around these issues by doing stuff like statistical modeling to guess the conversion rate, but this has obvious downsides and makes everything harder, which puts them at a competitive disadvantage vs. vertically-integrated players like Apple and Amazon.

By virtue of everything sold on Amazon being in the Amazon app the rule in question is kind of moot. The ATT privacy rules don't matter to them because they've already got everything they need to know about you from your habits in their app.

Business didn’t have to compete with Amazon in so stringent conditions. People even were able to (gasp!) maintain physical stores, etc etc etc

You say that, but what this rule has done is made it so this kind of tracking is available only to large apps like Amazon. The little guy gets snuffed out before they can even gain traction.

I've been saying for years—and it's been received un-popularly here on HN—that ATT has been a bad thing for the industry overall, and this thread is a primary case in point.

If ‘industry’ is selling cheap tat by invading privacy then anything bad for that is good for society.

Are its unintended consequences in propping up monopoly also good for ‘society’, then? Hate to break it to you, but the topic is a bit more nuanced than ‘privacy good’ ‘ads bad’.