The "page" feature of Facebook is designed to provide a way for people to become fans of people, organizations, bands, etc. These fan pages are available to people who do not have Facebook accounts and administrators of fan pages have the ability to send updates to fans. Anyone with a Facebook account can create a fan page about anything, even things for which they are not the authority.
Imagine that I were to create a page for something generic, like the Sun. Now really, who isn't a fan of the Sun? Imagine that hundreds of thousands of Facebook members become fans of my page for the Sun. Now I have the ability to send "updates" to all of the fans of my page. Have a look at this blog post if you'd like to get a peak into the mind of the folks who are doing this kind of thing.
Personally, I don't want to give someone that kind of access to me on Facebook so I stay away from anything that asks me to become a fan of a page for a generic thing or concept like air, water, electricity, Fridays, toothpaste, tigers, etc.