during peak hours when service is most likely to be affected by overcrowding, heavy users only make up a small percentage of those consuming bandwidth – 14.3%, to be precise. And of the heavy users, only half of them were on the fastest connection, further driving home the fact that while they may consume more in total, they are not contributing more than anyone else to the actual problem, which is slowdown in peak hours.
Source: Another Study Shows Data Caps Are Likely Ineffective, Address Wrong Problem | TechCrunch