kind of true except if you've got 1000's of customers it all evens out and your traffic profile is actually quite smooth if you've got say 6 X 100G transits, 4 X 100G IXP ports and 5 X 100G PNIs then the impact of an individual 1G customer is not even noticeable, honestly. We can work to 1Mbps 95%ile being about 250GB of total transfer at scale.
I completely agree. The product being sold has only a loose connection to the cost incurred by the provider. This is why the product being sold is being sold in a vague / loose-ish way, because for the overwhelming majority of customers, the product being sold can be sold for a profit.
