  Mobile app developers use paid advertising campaigns to acquire new users.
Marketing managers decide where to spend and how much to spend based on the
campaigns' performance. Apple's new privacy mechanisms have a profound impact
on how performance marketing is measured. Starting iOS 14.5, all apps must get
system permission for tracking explicitly via the new App Tracking Transparency
Framework, which shows the users a pop-up asking if they give the app
permission to track. If a user does not allow tracking, the required identifier
to deterministically find the online advertising campaign that brought the user
to install the app is not shared. Instead of relying on individual identifiers,
Apple proposed a new performance mechanism called conversion value, which is an
integer set by the apps for each user, and the developers can get the number of
installs per conversion value for each campaign. However, interpreting how
conversion values are used to measure the campaigns performance is not obvious
because it requires a method to translate the conversion values to revenue.
This paper investigates the task of attributing revenue to advertising
campaigns using the reported conversion values per campaign. Our contributions
are to formalize the problem, find the theoretically optimal revenue
attribution function for any conversion value schema, and show empirical
results on past data of a free-to-play mobile game using different conversion
value schemas.
