OTOH, knowing that Cogent loves splitting the global Internet is one
good reason to not contract their services.
I think they sell traffic to their private Intranet. Which is huge,
but doesn't encompass the whole Internet.
But that traffic was likely requested by and for the benefit of the person the traffic is being sent to.
I’ve always found the argument that the quantity of traffic is the indicator of who should pay to be questionable.
If I’m an end user on an eyeball user and request a big download or streaming from a provider, isn’t it me that caused that traffic to flow? One could argue that I am the one that needs to pay.
On the other hand, one could argue that it’s the provider of the content that I requested that needs to pay, since it’s their content which is being distributed.
When you get to peering between two providers it’s almost impossible to decide who needs to pay. As I mentioned above, passing that traffic is actually to the benefit of both providers.
About the only settlement I could see is where one of the providers is bearing most of the transport costs. For example a regional provider only peering at one exchange point might expect some settlement costs with a big international provider that is effectively carrying their traffic both directions around the globe. But the quantity of that type of traffic is likely minimal in the grand scheme of things. Even then one might argue that connectivity to the small provider is still valuable to the customers of the large provider.