After Supreme Court refused to consider Apple's (and Epic's) appeals today, Apple published its guideline for apps in the U.S. that provide external purchase links:
In addition to using Apple’s convenient, safe, and secure in-app purchase system, apps on the App Store in the United States that offer in-app purchases can also use the StoreKit External Purchase Link Entitlement (US) to include a link to the developer’s website that informs users of other ways to purchase digital goods or services. To use the entitlement, you’ll need to submit a request, enable the entitlement in Xcode, and use required StoreKit APIs. Apple will review your app to ensure it complies with the terms and conditions of the entitlement, as well as the App Store Review Guidelines and the Apple Developer Program License Agreement.
Among other things, the following screen will be shown to the user each time the app calls the StoreKit External Purchase Link API:
Apple is so good at following the text of the ruling.
Apple is charging a commission on digital purchases initiated within seven days from link out, as described below. This will not capture all transactions that Apple has facilitated through the App Store, but is a reasonable means to account for the substantial value Apple provides developers, including in facilitating linked transactions.
Apple’s commission will be 27% on proceeds you earn from sales (“transactions“) to the user for digital goods or services on your website after a link out (i.e., they tap “Continue” on the system disclosure sheet), provided that the sale was initiated within seven days and the digital goods or services can be used in an app. This includes (a) any applicable taxes and (b) any adjustments for refunds, reversals and chargebacks. For auto-renewing subscriptions, (i) a sale initiated, including with a free trial or offer, within seven days after a link out is a transaction; and (ii) each subsequent auto-renewal after the subscription is initiated is also a transaction.]
L.O.L. How would any developer actually adopt this?
This is not surprising though. This is so modern-day Apple.