I was trying to explain to my dad on Saturday what RSS was and I came up with this analogy:
Web content is like pizza and there are a couple of ways to get your pizza. HTML is like having it "to stay." Web pages written in HTML are all about getting you to come in, stop in one place and spend some time on it. RSS is like getting your content "to go"--no tray, dish, glasses... just your food in a box, formatted to be sent exactly where you want it, when you want it. E-mail content from a website is like having pizza sent to you as well, in that same box, just not always when you want it, which is hardly convenient at all.