Apple announced a pilot program called “contingent pricing for subscriptions” yesterday that will let App Store developers automatically offer discounted subscriptions for users of other apps. Developers, the company says, will be able to base this on subscriptions “from one developer or two different developers,” which lets them not only to entice customers they already have to their other apps, but also compete by offering deals to their competitors’ subscribers.

There’s a slight catch here: According to 9to5Mac, the discount is only good while the customer’s other subscription is active. So if someone tries an app because it offered a deal and decides to cancel the other subscription, they’ll go back to the normal price. Apple also reportedly told developers that these discounts can be used in App Store advertising and marketing outside of it, in addition to within the app itself.

It could be a while before the benefits of the program are visible out in the wild, as Apple says it is bringing developers on board over the “coming months.” It’ll be interesting to see how it affects subscriptions on the platform as developers start competing with this new tool.

On its face, the feature sounds like a win for developers, at least as long as it doesn’t only benefit bigger developers who can afford to offer such deals. Growing the App Store’s appeal is something Apple will continue to need to do as regulatory pressure on its digital store’s supremacy mounts. Although the company emerged mostly unscathed by its antitrust fight with Epic, the Fortnite maker just notched a stunning win against Google, which could embolden future challenges to iOS App Store lock-in.

In the EU, where Apple will soon allow third-party app stores, simply having a store won’t be enough — Apple will have to make it attractive for developers and customers, too. That means helping developers make the most money they can for their efforts, and giving them more ways to compete for customers is part of that.