The ancient Greeks put a coin in the mouth of their dead, to pay Charon for the crossing to the underworld.
They did not argue about who should pay the ferryman.

On the internet, there are many providers between you and YouTube.
Who pays them? Or, to put it more pointedly, who is allowed to charge whom for the service?

This is about "network neutrality" and remains a topic of intense discussion and legislative action.  

On the one hand people argue for "universal service", saying that one person's bits should not be treated differently from another person's.
This compares to the idea that a phone company should not be allowed to treat your calls differently depending on what you want to say, or that red haired people would have a different monthly fee.
There are laws against this type of discrimination (at least in most nations), and some people want to extend these laws to internet traffic.

On the other hand there are some internet providers who want to charge different customers different rates for different service. "We can't have companies freeloading on our expensive pipes", they claim.
Clearly we seem to want both.
We don't want the network providers to decide which traffic gets carried, and we also don’t want a bland one-size-fits-all service that is expensive for some and inadequate for others.

My idea is that the issue is a bit oversimplified, and will become more clear if we use the right model of who connects to whom, as well as who pays who. This model recognizes more types of players, instead of just the network providers on both ends of the connection, as we were used to in the telephone days.
There is the client ISP, which connects the access devices such as PCs and smartphones, and the server ISP, which connects the website hosting to the network. They both charge money to the owners of the respective devices. Their interconnection is either direct, or through so called "transit providers". They both typically pay the transit provider (unless the ISP is really big, in which case it can probably negotiate free transit, called peering, with equally big ISPs).

To me it seems that the discussion on net neutrality can be framed in the following way. Can the client ISP charge the ISP connecting a specific server? I.e. can Comcast charge Netflix and not YouTube, for providing the bandwidth for videos? This would seem odd, as the entire service of hooking up Netflix and YouTube is already provided by their internet provider. At the same time, Comcast can charge the home customer more for higher speed service. The provider of the hosting company can also charge them for better service.
So the question will then be reduced to: can a provider charge another provider with which it does not have a direct business relationship?
Does it have that power? Is it allowed to have that power?

That question becomes even more interesting when viewed through the lens of promise theory.
The client ISP promised a certain internet access service quality.
Charging the content provider means the same promise is sold twice.
If the content provider refuses, and service quality is dropped, the promise to the consumer is broken.