I noticed some time back that the (very pretty looking) iBooks app is not a built-in app on the iPad, even though it was demo-ed and talked about quite a bit at the iPad launch event. It’s a free download from the App Store instead, and like others I’d been wondering why.
I think the reason put forward in the tweet above from @perfy to John Gruber (of Daring Fireball) is a very good one.
Rather than having to wait on OS updates to tweak the iBooks app, it can be updated whenever, just like any other App Store app – except probably without rejections backed by loony tune reasons and such-like. :)
Via: Daring Fireball
To my understanding, the reason to do so is to limit the delivery of the iBook app to specific regions. I.e, only where Apple has esteblished a relation with local book publishers will the iBook app be available. At first it will be available only to US customers. Then Canadian, European and so on.
Hmm, that's another quite logical sounding one. That way it can be rolled out to each store as publisher arrangements are tied up.