So, here’s an early version of a workbook that can be used to help the Tableau Server Administrator keep an eye on what’s happening with VizAlerts on their server.
To publish, do the following:
Some info on how to interpret the data in various sheets is embedded as Captions.
If you want to get an alert when someone signs up for a new VizAlert, you can do this by setting up a daily Alert subscription to the Alerting Overview dashboard, but because there’s no date field to tell you when the subscription was created (sigh), you’ve got to reset the Max Subscription ID for Alert parameter each time you get an alert. It's best to set the parameter, save the view as a Customized View, then subscribe to that, because it's way easier to reset the parameter on the fly that way (you avoid having to to republish or web edit your entire workbook).
Like the title says, this is an early version that I've been using for awhile to manage VizAlerts running on my own Server instance. Doubtless it can be improved, so let me know what works and doesn't, and any recommendations you might have. Once it stabilizes and proves to be useful, I can add it to GitHub.