A slew of internal emails were revealed today, showing how Apple execs battled with Amazon over allowing in-app ebook purchases in the Kindle app.
Back in 2011 users can purchase ebooks on Kindle via the app, but it has been changed so the app could not buy ebooks directly on the iPhone or iPad. It’s said that Amazon made it this way so they could avoid giving Apple 30% in ebook purchases.

Schiller emailed Jobs and other Apple execs and presented the idea that they could drop the feature as an Amazon video ad showed how iOS users could make the switch to Android and still get access to all their ebooks. Jobs’ response was to force Amazon to use their payment system or ‘bow out’. Furthermore, he reiterated that iBooks should be the only iOS bookstore in Apple devices.
These emails were sent in the time when Apple was about to announce App Store policy changes in its subscriptions.