I'd like to change my app to have a flat monthly fee and 1% of monthly sales.
Is usage-based billing the best practice for this?
One downside of usage-based billing is that the merchant needs to approve a daily max limit of what the app can charge them. If I set this too high, some merchants will be daunted and decide to not install the app. Wondering if others have similar experiences with this.
If no anecdotal answers are forth-coming on this board you may have to dig around for posts about revenue share, percentage billing, or terms around "credit"|"coin"|"units" or similar based private currency usage schemes that use the AppCredit,etc and reach out to the posters.
May also want to hit shopifypartners slack chat.
You should just be able to apply it as many times as needed or use progressive optin by updating the charge:
Setting max daily limit - consider setting the max limit to correlate to the shopify plan, and having a partner friendly test tier when reasonable ;)
If you have a really unique offering and have proven revenue generation data, or testimonials, then probably don't be afraid to scale a bit logarithmically while staying competitive. As a merchants plan amount increases it's very easy for an app to go from nice-to-have-lets-test-it to business requirement.