ISPs would never charge customers depending on the product because measuring that is practically impossible. They never even wanted to do that nor advocated doing so (this was a major source of misinformation put out by the pro-net neutrality camp). What they do want to do is bill the service, namely very large companies that use tons of data, for example earlier Netflix, for the cost of the infrastructure build out they need to do. They're not interested in small companies that produce small amounts of data, nor the end users. They're interested in recouping infrastructure costs from those that drive it upward, which isn't end customers.