The Fallacies of Distributed Computing Reborn: The Cloud Era

Let's take the typical example of a photo editing app. Robust sync ameliorates a lot of these issues. You might lose your connection. Not so big a problem if you have your own local copy. One of the administrators is doing something that shuts off access to one copy of your data -- you still have another copy. The network is slow -- with synced data, you just have to send deltas.

Robust sync doesn't completely solve everything, but it takes these problems -- which are often edge cases -- and it reduces their impact.