While having our apps, if there is any change on the customer’s app package (like plan upgrading or downgrading), your commissions will be adjusted accordingly.
For example, you refer customer A to install an app at $29.99 for Basic Shopify plan. After 14 day free trial, if A continues to use the app, with your commission rate 20%, you will then receive $29.99*80% (20% Shopify fee)*20% (your commission) = $4.798. Next month, If A upgrades to a higher plan (eg: $34.99), your money will increase at $34.99*80%*20% = $5.598.
The longer they have our apps, the more money you can make.