Whether wild and crazy or normal and boring, subscribing to calendars can definitely be informational. For example, I like NASA, and it would be great to have their launch schedule as part of my calendar in a way that it's always current (by someone in the know).
I subscribe to several calendars this way, and use iCalShare.com to do it. It's a one-stop-shop site that allows anyone to create and share a calendar that they maintain, thus allowing people like me to subscribe to it.
In order to use iCalShare, you need to be using a calendar app that supports the iCalendar format. Examples of this would include Apple's Calendar app (part of OS X) and Microsoft Outlook.
If you have an interest in something that doesn't already exist, don't be afraid to create and share it yourself. There's a good chance that someone else has the same interest!
