I'd like to stress what the article says about the difference to other caffeinated drinks. I drink coffee a lot, since it is more easily available, but I prefer club mate if I can get some. For work it is much better than coffee. I tend to get very shaky and restless from coffee, my leg will start bouncing after a lot of programming (i.e. concentrated work periods in front of a computer). With mate the caffeine rush is much better, I stay more focussed and can concentrate more easily. I am not as restless. Yet it is possible to overdose. One bottle can last for hours, I bet the guy in the article could look through time after 10 bottles a day. If you can get it, try it!