Installs are a vanity metric. We optimise to registration and revenue.

App-install costs vary depending on the app category, audience, platform, geography, competition, campaign objective and quality of traffic. There is no single CPI that applies to every app.

Cost Per Install, or CPI, measures the average amount spent to generate one app installation. It is calculated by dividing total advertising spend by the number of attributed installs.

If the business ultimately needs registrations, purchases or subscriptions, optimising only for installs may not be enough. The acquisition funnel should be evaluated from install → registration → activation → purchase or subscription → retention.

Both platforms can be useful for app user acquisition. The better option depends on the app, audience, acquisition objective, creative assets, conversion data and the downstream actions that matter to the business.

The required budget depends on expected CPI, audience size, campaign objective and the amount of conversion data needed for optimisation. A campaign should be planned around the desired downstream outcome rather than installs alone.

Important post-install events can include registration, activation, purchase or subscription and retention. Tracking these events helps determine whether advertising is generating valuable users rather than simply increasing installation numbers.

ASO, or App Store Optimisation, focuses on improving an app's visibility and conversion within app stores. Paid user acquisition and ASO can complement each other because paid campaigns can generate users while app-store optimisation can improve the effectiveness of organic and paid traffic.

A mobile measurement platform can help businesses measure attribution and understand where app users are coming from and what they do after installation. The right platform depends on the app's tracking requirements, advertising channels and measurement needs.

Apple's privacy changes have affected how advertisers measure and attribute app activity. App marketers therefore need an appropriate attribution and measurement setup to understand campaign performance while working within platform privacy limitations.

Once sufficient data is available, app campaigns should increasingly be evaluated according to meaningful downstream actions such as registrations, purchases, subscriptions or revenue rather than installations alone. The appropriate optimisation event depends on the app's business model.