The wonderful world of RSS

OK, so I'm a little late to the game--everyone but me seems to know about RSS feeds. What a great tool! But I was surprised to find how many web sites do NOT have RSS feeds available yet. Are government and nonprofits behind the times? (I write and edit materials about Alzheimer's disease and healthy aging, so I searched some of my favorite sites on those topics.) I ended up subscribing to feeds from Medlineplus, the Centers for Disease Control and Prevention Communications Office, and the wonderful New York Times blog called "NewOld Age." I wonder, though, how RSS feeds differ in function from many websites' e-mail alert services. It seems like the end result is the same.