This is massive news for any developers that were considering adding a sync feature to their apps. Even just local sync is a headache to implement from scratch, to say nothing of cloud sync – and what Apple just announced is a complete, unified solution from system-level APIs to servers, all ready-made and awaiting some Cocoa calls.
Android has had this feature for over a year. Shocking, right? This is what Diaspora should have been at the base. (Note, Camlistore might be interesting for those interested in these sorts of things)
I agree that this is really cool, but I'm a little confused about the details. Surely they must charge the app developers for the space they use up in their new fancy (and expensive looking) data center? Steve said that app files didn't count to your personal 5GB storage, so where does apple recoup the costs?
I do not know what Steve said, but the way you state it, "app files" could be the files in the application itself, not user files made by an app. For performance and robustness, they will have more, but they need only one copy of those on their servers, and it could be the one in the App Store. The costs of storing those are a) peanuts, if you are Apple, and b) possibly recouped by the $99 developer fee.
You're probably right that "app files" they way steve mentioned is does refer to the data of the apps themselves which isn't a lot of data.
I was more curious about data files that are used by an app (I'm assuming we can use the iCloud API to synch those between devices) - how is that paid for? does that count towards the 5GB limit? If so, can you get more space? at what cost?
For example, right now GoodReader uses the dropbox API to allow cloud access to whatever documents you have, and I have several gigs of various .pdfs that I store there. With the iCloud API, can Goodreader abandon dropbox and let apple host them?
They recoup the costs when you buy the highly marked up hardware. I know I've certainly bought enough of it over the years. Apple has incredibly high margins on these devices, and this service is to sell more of them. It's a brilliant plan and everybody more or less wins.
But you had to convince your users to sign up for something that costs $100 per year. Now it’s free and comes by default with any device running iOS. That’s a rather significant change. (Oh, and that functionality is now open to iOS developers which are a much bigger deal than Mac developers.)
(And not to gloat, but I pretty much called this a week ago: http://news.ycombinator.com/item?id=2603921 )