> Apart from one-off costs for building the line... That's where the majority of the cost is. It may appear to be a one-off cost, but it's a capital expenditur

> Apart from one-off costs for building the line... That's where the majority of the cost is. It may appear to be a one-off cost, but it's a capital expenditure that's huge, and such capex is financially equivalent to an ongoing cost of capital (https://en.wikipedia.org/wiki/Cost_of_capital https://en.wikipedia.org/wiki/Cost_of_capital). Since individual connections each have some peak bandwidth capacity, that ongoing cost is proportional to peak bandwidth usage. So ISPs need to ensure that they have sufficient capacity at peak time. That's where their costs are. One way to achieve this is to ignore the problem and effectively throttle customers at that peak time by under-provisioning. Another way is to discourage customers from maxing out their connections over peak times using monthly transfer limits.