It is very handy. And what I love about it is it's not as bothersome as email. When you subscribe to a site via email, you often feel obligated to read the email when it arrives and if you get a lot of emails, it can be overwhelming. I tend to have a lower tolerance for email.
If I get 1-2 emails from a sender that I'm not interested in, I'll probably unsubscribe.
With RSS, I find myself to be much more tolerant. I can skip over the content that doesn't interest me and read the good stuff at my leisure. What a great concept.