:: No database
Threads are just RSS feeds. When a reply is added, a new item is added to the feed.
:: No hoops to jump through
No registration, no e-mail confirmation, no CAPTCHA. Just type your message, give a name and password you want to use and your post is made. Use the same name / password pair in the future to keep the same name, it’s that simple.
:: No clutter
No user profiles. No "status updates". No signatures. No user ranks. Just pure discussion with none of the cruft.