$5 a month for unlimited backup with Carbonite.com

Carbonite.com has a $5 per month for unlimited storage backup plan. I’m a bit skeptical of why this price is so low, but that’s the price they advertise.
There’s a nice comparison chart showing prices of the competition on their site which shows that this clearly is a “price” play.
Carbonite.com’s web site reads – Carbonite online backup software is always looking for new data on your PC. The moment you add or modify files, Carbonite swings into action to back up your data. Whenever your PC is connected to the Internet (at home, the office, a hotel or airport) Carbonite is working to keep your data safe. And it will never slow down your PC or Internet connection.
Smallbusinesscomputing writes When first used, Carbonite offers subscribers the option of backing up the entire disk or just files contained on a PC or laptop’s Desktop and My Documents folders. However, the always-on service does not backup system files, executables or temporary files, and will not backup files larger than two gigabits since this would take too long, Friend added. Software installed on the subscriber’s PC will constantly look for and mark new and updated files for backup when connected to the Internet.