IPM stands for Installs per Mille. It is a metric that is used to track the number of app installs per thousand ad impressions. It is often used as part of a mobile advertising or user acquisition strategy which aims to buy new users for an app. When ad spend is targeted only to potential new users who have not installed the app, IPM provides useful insight into the conversion rate of new users. Moreover, improved IPM has the added benefit of boosting the rank of the advertising campaign in advertising networks waterfalls, which in turn results in higher volumes of ad impressions and installs.