Set SKAdNetwork conversion values
Conversion value (CV) is the primary performance metric for campaigns using SKAdNetwork postbacks.
An SKAdNetwork conversion value is a 6-bit binary value, each representing a post-install event or action defined by the advertiser or publisher. It has 64 possible configurations, measured as an integer between 0 and 63. The 0 is reserved for the install itself.
When a user clicks on your ad and installs your app, they initiate a 24-hour postback timer. The install represents the first conversion value action. Each time the user completes an in-app action with a higher conversion value, the timer resets to 24 hours. When the timer expires, Apple sends a postback that contains the install and the user’s final conversion value to Unity’s ad network.
Most MMPs provide templates and tools for mapping in-game events or revenue to conversion values. Unity does not require you to adhere to a specific conversion model, and the best model may differ for each advertiser. However, Unity does recommend the following best practices.
Conversion values should be incremental
Assign events in ascending order of value according to some key metric. For example, if you’re tracking player value, then users that make an in-app purchase are usually associated with a higher average value than users who watch a rewarded ad.
Limit conversion value updates to the 48-hour period after install
While there’s no limit to how many times you can reset the conversion window, the measurement period should be fairly brief. The last update should occur within 48 hours of install. By this time, the typical retention curve is already flattening, and 50-70% of your paying users have made their first purchase. This should be enough time for you to rank ad network and campaign performance, and to identify the most valuable sources.
Simplify
More granular measurement is not necessarily better. The SKAdNetwork framework provides source app IDs and conversion values instead of identifying individuals, which makes it difficult to track events that your users are unlikely to perform unless you have very high install volume. Unity recommends mapping your conversion values to relatively common events that split your user base into approximate groupings of the top 10-20%, the next 20-40%, and so on.
Experiment
While the industry is still in a transition and learning phase, Unity believes that the best way forward is to start with something simple and follow an experimental, iterative approach along the following steps:
- Start using conversion values for reporting, alongside more traditional, granular metrics.
- Users who give their permission for tracking will provide a reliable benchmark for your conversion value-based reporting.
- Experiment to find the best way to set the conversion value to optimize your user acquisition budgets based on user value and return on investment.
Over time, ad networks will build on these initial learnings and start using conversion values to encode source app quality into their optimization algorithms.
Baseline recommendation
If you’re unsure about where to start with conversion values, Unity recommends the following baseline setup using the conversion value to track the number of sessions within the first 48 hours of install:
| Event | Conversion value | Session number | Share of installs |
|---|---|---|---|
| Install | 0 | 1 | 33% |
| Second Session | 1 | 2 | 23% |
| Third Session | 1 | 3 | 13% |
| Fourth and fifth session | 3 | 4 and 5 | 15% |
| Sixth-plus session | 4 | 6 | 16% |
Note: At install, the app calls registerApforAdNetworkAttribution. For the second and additional sessions, the app calls updateConversionValue. Higher numbers of sessions in the first 48 hours correlate with higher retention and LTV, so this is a good starting point for you to track the quality of installs you're receiving. You can continue to experiment and build on this to find a conversion value setup that is optimal for you.