In real life it is important to walk the way you talk. The same is also true in the mobile subscription world. One of the biggest reasons that your users leave your app is that their expectations weren’t matched by the reality of your app.
This can have several root causes but statistics show that 53% of all causes of customer churn are due to three leading causes and the first one is poor customer onboarding with 23%. In fact this is where your users tries to figure out your app, discover features and use it appropriately. Bad UX can hide useful features from the user and become a frustration point. This is why it is critical to have a clear onboarding flow.
Another issue is overselling: this can be done on several steps through the funnel: your ads, your app AppStore page and your flow until the paywall all leave an impression on the customer. If (s)he can’t find what was promised during these steps in the app, (s)he will be likely to leave and can even ask for a refund which can have grave consequences.
This step is critical both in improving AtS performance and reducing churn so its impact is twoful and therefore can be prioritized.