[ar_lan]

> The exact words used by the Audible app for iPhone: This app does not support purchasing content. Instead, add to your wishlist.

I honestly never really thought about why this is - I simply just hated Audible for it, and thought it was the most annoying part of their app.

However, it's odd - how come the Amazon app is allowed to get away with its own purchasing system?

[jordanthoms]

I believe there's an exception for physical goods, so Amazon is ok but not Kindle, audible etc.

[MaxBarraclough]

You're right, and I was mistaken -- the Amazon app for iPhone lets you checkout.

I believe jordanthoms's explanation is correct.