Sign up and find out. If you're Ninja-Approved, you'll earn many awesome rewards.
After you sign up, you'll receive your Ninja Application via email. Fill it out, and come back to post your first Tweet. Post and earn points to redeem if you're Ninja-Approved.
Ninja Approval is granted only to a select group. (Hint: We like prolific Twitter posters - quantity and quality count!) Keep posting, because we're watching.