A free case of Hint Water sounds nice. However, in order to get this free case you have to complete ten days worth of challenges. I'm not exactly sure what those challenges may be as I just signed up last night.
If you'd like to try and get a free case of Hint Water just go here and click where it says "Take the Drink72 Challenge". Then you'll enter your name and email address. Soon after that you'll receive a welcome email. In that email they tell you that you'll get a water drinking tip and have to click on the link to say that you have completed that days challenge. At the end of the ten days if you have completed all of the challenges you should get a form to fill out so they know where to send that free case of Hint Water.