If you're a user or system administrator pondering the use of Subversion, the first question you should ask yourself is: "is this the right tool for the job?" Subversion is a fantastic hammer, but be careful not to view every problem as a nail.
If you need to archive old versions of files and directories, possibly resurrect them, or examine logs of how they've changed over time, then Subversion is exactly the right tool for you. If you need to collaborate with people on documents (usually over a network) and keep track of who made which changes, then Subversion is also appropriate. This is why Subversion is so often used in software development environments — programming is an inherently social activity, and Subversion makes it easy to collaborate with other programmers. Of course, there's a cost to using Subversion as well: administrative overhead. You'll need to manage a data-repository to store the information and all its history, and be diligent about backing it up. When working with the data on a daily basis, you won't be able to copy, move, rename, or delete files the way you usually do. Instead, you'll have to do all of those things through Subversion.
Assuming you're fine with the extra workflow, you should still make sure you're not using Subversion to solve a problem that other tools solve better. For example, because Subversion replicates data to all the collaborators involved, a common misuse is to treat it as a generic distribution system. People will sometimes use Subversion to distribute huge collections of photos, digital music, or software packages. The problem is, this sort of data usually isn't changing at all. The collection itself grows over time, but the individual files within the collection aren't being changed. In this case, using Subversion is "overkill". There are simpler tools that efficiently replicate data without the overhead of tracking changes, such as rsync or unison.
 Or as a friend puts it, “swatting a fly with a Buick.”