Although everyone seems to agree that user acquisition is a big problem for mobile game developers - it's too expensive - all mobile game developers with access to money partake in UA.
The reason is simple.
If you can gain users who spend more money in your game than you spend in marketing to get them, you have a perpetual money making machine.
And that's why all developers with any money will spend up to (and sometime over) that marginal level of profitability.
Yet, changes to iOS 10 have the potential to seriously shake up this equilibrium.
Leave me alone
Apple introduced the Limit Ad Tracking feature in iOS 9.
It allows people to limit the information they send to advertisers, but the system still generated a unique ID per device, which could be used for some advanced features, such as fraud detection and debugging.
Industry estimates suggest around 10-15% of users have Limit Ad Tracking switched on.
And it's this that Apple is removing in iOS 10.
The result will be that anyone with Limit Ad Tracking switched on will send back a zero ID (00000000-0000-0000-0000-000000000000) to advertising tracking platforms.
Obviously, for UA companies, this is a disaster.
The better information they have on users - location, gender, age, device, what apps they have installed etc - the more they can charge to run an advert.
For example, a young guy working in New York with an iPhone 6 Plus and who's regularly playing Mobile Strike is just about the most valuable install candidate on the planet, at least in terms of game UA.
But if he switches Limit Ad Tracking on, he becomes as valuable as a Chinese toddler with his dad's old cracked iPhone 5C.
Trouble ahead
Industry estimates suggest around 10-15% of users have Limit Ad Tracking switched on.
That's really worrying, given that people who can find and tap on the iOS Setting button are more likely to be tech savvy, have more up-to-date devices, be more likely to play games, and more likely to spend money in games.
On that basis, that 10% figure is something of a Trojan House: the percentage of iOS game revenues currently generated from players with Limit Ad Tracking switched on will be a lot higher, and that will be money forever lost to the UA sector.
Bizarrely, this disruption could be a good thing for some game developers in the short term.
These big spenders won't be trackable, but will still be served mobile ads, so you might end up paying very low rates for very valuable users.
Yet, the point of UA is that it's not a crapshoot. Anything that damages the repeatability of the experience, damages the entire sector.
Indeed, mobile monetisation outfit Tapjoy says it will display a message to tell game players who have switched Limit Ad Tracking on it's the reason they won't now be able to earn in-game currency as part of Tapjoy's rewarded video ads system.
Making UA more complex and less effective makes Search Ads more attractive.
More apocalyptically, mobile ad company Fiksu argues "advertisers cannot absorb this loss of data even at the current levels".
Apple's long game?
Similarly, it's not clear the mobile experience will improved for people using Limit Ad Tracking.
It's not an ad blocker, and as Apple points out, "If you enable Limit Ad Tracking, you may still receive the same number of ads, but the ads may be less relevant to you".
In this context, it's a wonder why Apple has implemented the feature at all.
Conspiratory theoretists will point to sunsetting of its iAd network and the introduction of App Store Search Ads - also in iOS 10.
Making UA more complex and less effective makes Search Ads more attractive.
