An AVERAGE of 5 hours per user...EVERY user...do you have any concept as to how much that really is? And since there are almost certainly a bunch of people that don't touch it at all, the folks that are actually using it are using it quite a bit more than that. That's how averages work...
For example, I can say based on 2012 statistics that, on average, every American smoked about 0.01 cigarettes that year. But this is counting the vast majority of Americans who never smoke at all. Also, infants and small children. 0.01 sounds like barely anything, but when you consider that there are 300 million Americans...well, the math speaks for itself. We still have a very large cigarette industry, despite the overall decline of smoking in the USA.