Conversion Rate and CPI

Image for blog post, aimed at enhancing the visual appeal and providing context for the content.

The Conversion Rate is the ratio of users who install your app to the ones who visit your App Store page. Let’s visualize the moment when the user decides to install an app. By tapping on the “Get” button on the App Store and then confirming this action, the user knows that (s)he will have to wait for the app to download and then discover a whole new experience. Waiting AND learning something new is a pretty big commitment these days so by clearing this step you know that the user is motivated to use your app. This is why the Conversion Rate is very important (getting the installed app to be a subscribed one is a whole different adventure, as explained in our ItS article).

A low CR means that either your ads are completely out of sync with what you show in your App Store page or that your page’s components are not optimized to drive downloads.

Other than comparing your ad content to your App Store page content, you can check & improve three main sections of your page.


Your app icon, the video and screenshots you use on your App Store page showcase your app: they need to be sharp & compelling. You can find a detailed article on App Store visuals here.


The description of your app from a Conversion Rate perspective has the user as the audience and needs to be clear and concise. (This is in opposition with the “discoverability” perspective which has the algorithms from Apple and Google as the audience and is useful to bring users to the page, not convert them). Don’t forget that only 2% of the users tap the “read more” button, so it all happens in the first sentence that is visible from a CR perspective: the rest is mostly used for ASO (App Store Optimization – i.e.: discoverability of the page).

Ratings & Reviews

The assurance that other people like the app is pretty important in the human psyche and this is why your ratings and reviews are key elements in improving the CR. (They are also important from a discoverability perspective since Apple mimics this human trait and makes the apps with better ratings & reviews more visible on its App Store).

To illustrate, only 50% of users download a 3-star rated app whereas more than 90% download a 4 or 5-star rated app. But bear in mind that while getting to at least 4 stars is critical, you might want to limit your efforts to get higher ratings since achieving higher rates will have a lower impact.

Cost per Install (CPI)

The Cost per Install (CPI) is simply the money spent on ads, divided by the number of users who install your app. The CPI depends both on the effectiveness of your ad channels (and their respective Cost per Tap – CPT) and your CR. It should be noted that an ad channel with very low CPT can also bring in users with very low CRs, so when comparing ad channels, consider comparing CPI and ItS levels instead of just looking at your CPTs.