Why use Joel's premium subscription service?
Because you have a busy life and can't just drop everything for a cheap trip. You want to customize trip alerts for times when your kids are out of school, or during weekends/holidays that allow you to take as little time off from work as possible.
Because you're tired of opening emails from other subscription services to find out the airfare in the subject line is only if you fly out of a different airport 500 miles away.
Because when you join, you'll be directly responsible for giving back to your community. For every paid membership, public-servants, volunteers, and teachers who are working hard to serve your community get a free membership to just get out of town too.
Because this is a grass-roots effort from a guy with a passion for travel who needs your support and you like the idea of saying "I was there since the beginning."