Apple, which takes 30% commission on all digital content bought within iOS apps, flagged up the new guidelines requiring publishers and retailers to remove links to their own websites from their apps in February this year.
It has been reported that Apple began enforcing the guidelines more heavily last week and rather than pay the commission, a number of publishers have stopped selling content through their apps.
Google temporarily took down its ebook reading app from the App store yesterday (25 July) but restored it, without the ability to buy books. Google declined to comment.
Amazon also updated its Kindle app yesterday, removing the link to its store. On its forum yesterday it posted: "In order to comply with recent policy changes by Apple, we've also removed the Kindle Store link from within the app that opened Safari and took you to the Kindle Store."
Rather than give Apple a share of in-app ebook sales, Amazon’s statement advised users to visit the Kindle store via the Safari browser.
Over the weekend, The Wall Street Journal and Kobo, the Canadian ebook retailer, removed external links to their sites and no longer sell content to customers through their apps for Apple devices.
Apple did not responded to a request for comment on the new guidelines.
Last month (7 June) the Financial Times launched a web-based app in HTML5, as a way of circumnavigating Apple’s 30% subscription transactions for its iPad app.
The move was also due to the publisher’s concerns over the lack of data Apple disclosed about the behaviour of its app users.