In most cases the schedule will be set by the business and that schedule will be automated so the DBA probably won't be doing much with it.
For me, most of the uses I have found have been related to reporting. I needed to capture data at a point in time to report on. I could copy the data or some other method but I couldn't easily just freeze a database in a particular state without snapshots.
One of the reasons to use them is they are very easy to setup and then the system handles the under the covers work.