In the "old days" the relationship between our IT staff and our customers was not as pleasant as it could be. This was mainly due to the fact that every time we heard from our customer they were either in a crisis or at the very least upset about a computer crash or a technical issue that had probably been festering for an extended period of time before it became unbearable which is when we would get the call. With a good managed services model we are able to reduce these stressful events by addressing issues before they fester. In most cases we will address the issue before the customer knows it's an issue. It may be an alert that the hard drive is getting full, or that there are read/write errors on the drive , or that the memory is being maxed out, etc. We can then go behind the scenes, run reports, examine CPU or memory usage for the last few days or weeks, check on virus activity, whatever it takes to get to the bottom of the issue.
Our remote access tools, as well as our management tools, are top notch. We can install and remotely manage antivirus software, backup software, Windows Updates. We can run scripts either manually or automatically when events occur like deleting temp files when a disk space alert is received.
We also do a majority of our work after hours to limit the downtime of our customers. We don't charge extra because it seems like common sense to us that a managed service provider should provide service when the computers aren't in use.