There's no such thing as a casual fan of metal. You are in all the way. To prove this, Danish car rental company Lej at Lig asked agency TN Reklame to promote Copenhell metal festival by using the Growl-O-Mete. A voice activated light sensor, kind of like the test Your Strength machine. They asked metal fans scream into the machine. The more powerful their growl, the more they had a chance at winning a discount on a car rental. A few hundred people used the machine. And now Lej et lig owns the coveted metalhead category. RAWK.