Not having to dial up is about the best damned feature.
Check your emails in an incredible short while. No fucking hassle, no morning routine (dial up, get coffee, open mail box, refill cup, click several link, do dished and prepare for mid morning snack...)
If you do any internet commerce, zipping though online catolouges is a breeze. You can easily view pictures of items you're buying, and browse many different brands without becoming bored with the task at hand. Its like going to a store, having every brand of the item you need right in front out you. No walking, no driving, sit, browse, buy.
Those two, to me, seem to be the drive to sign up for DSL to everyone I talk to. They either have a home business where they sell items online, and need to check email often, or tend to a website. Or, they have begun to use the internet as a primary means of communicating with friends/relatives, and reading allt he assorted emails/links they get sent is a major process with dial up. And really, its all mostly shit they send... the faster you get through it, the better!
Buying online is something I personally prefer. Im a MidwayUSA whore, and Ill browse the shit out of shooting products before I buy. I can rip around websites like you wouldn't believe, and gather a vast amount of information that a catolouge simple couldn't provide.
Simply put, you can do more, faster. A lot less hassle to get the simple tasks out of the way.