Apple is cutting commissions for affiliates for App Store apps and in-app purchases from 7 percent down to just 2.5 percent starting May 1st, as per MacStories’ Federico Viticci.

According to the document shared by Viticci, the changes only affect affiliate referrals for apps, with other iTunes and iBooks Store content like music, movies, TV shows, and books still receiving the 7 percent rate.

So, yeah, this change in affilate commissions pretty much sucks. We don’t rely on links alone (thankfully), but we’ll be affected by it. pic.twitter.com/85V94DBPqQ — Federico Viticci (@viticci) April 24, 2017

It’s a seemingly strange move on Apple’s part, given both the short notice (affiliates were given just one week of warning) and the dramatic rate of the cut (almost 65 percent).

And while most users won’t be affected by the changes, developers who rely on affiliate links for their apps to generate extra revenue could see a hit to their income. Given Apple’s focus on giving developers more revenue with initiatives like the changes to subscriptions last year (which gives developers who can maintain annual paying subscribers an improved 85 / 15 percent revenue split with Apple instead of the usual 70 / 30), it’s curious to see the company clamping down on a small but significant source of income for developers.

The move also has other, more subtle ramifications, given that many sites that cover apps (including MacStories, where Viticci serves as editor-in-chief) rely on affiliate links for additional revenue. Those sites could be forced to turn to other sources of funding, including more ads and sponsored content, depending on how reliant they were on the affiliate commissions.