What a Coarse Conversion Value Is
A coarse conversion value is the lower-resolution half of Apple's conversion value system in SKAdNetwork 4 and AdAttributionKit. Instead of a number from 0 to 63, it is one of three labels: low, medium or high. The app sets it alongside the fine conversion value, and Apple decides which of the two to release in each postback.
Apple added coarse values in SKAN 4 to fix a problem with earlier versions. In SKAN 3, a campaign that did not meet the privacy threshold got a null conversion value, so smaller campaigns reported installs with no quality signal at all. With coarse values, those campaigns still learn whether their installs were low, medium or high value.
When Apple Reports It
Whether a postback contains a coarse value depends on two things: which postback it is, and the install's crowd anonymity tier.
- First postback, days 0 to 2: a fine value at the highest tiers, a coarse value at the tier below, nothing at the lowest tier.
- Second postback, days 3 to 7: a coarse value whenever the tier releases conversion data.
- Third postback, days 8 to 35: a coarse value whenever the tier releases conversion data.
Two things follow. Every signal you want to measure after day 2 has to fit into three levels. And for campaigns without much volume, the coarse value is the only quality data you will ever see.
Designing a Coarse Value Mapping
The best coarse mappings are boring and consistent. Each level should describe a clearly different kind of user, and the same user should land on the same level whether you read the first postback or the third.
- Low: the user opened the app and did something basic, such as completing onboarding or registering.
- Medium: the user did something that predicts revenue, such as starting a trial, adding a payment method or adding to cart.
- High: the user generated revenue, or crossed a revenue threshold that matters for your payback model.
Leave a user without a coarse value if they did nothing meaningful, rather than defaulting everyone to low. That keeps low informative.
Later windows are where coarse values earn their place. A subscription app can use the third window to mark trial-to-paid conversions as high, a signal that would never fit into the first 48 hours. A shopping app can use the second window for repeat purchases.
How Networks Use Coarse Values
Ad networks receive the same postbacks you do, and their bidding systems learn from them. When high consistently means a paying user, a network optimizing for value can find more of those users. When levels shift meaning between campaigns or app versions, the network's model learns noise.
That is why most MMPs generate coarse values from the same event and revenue rules as fine values. In Linkrunner, you set the events, their priority and revenue ranges once in your conversion value mapping, and Linkrunner generates the fine and coarse values for Google and Meta from it. The SKAN dashboard then shows how installs split across low, medium and high by campaign and over time.
Reading Coarse Values in Reports
Read coarse values as a mix, not a count. A campaign with 40% high installs and a campaign with 10% high installs tell you more than a total install number, especially when both are too small for fine values.
Compare campaigns only after their windows have closed, because second and third postbacks arrive days or weeks after install. And keep a record of your mapping over time: if you change what high means, values before and after the change are not comparable, and campaign trends will look like they moved when only the definition did.