ISP shittiness aside, ISPs do actually pay for Internet backbone access by the byte. Usually there are peering agreements saying “you take 1tb of traffic from us, and we’ll take 1tb of traffic from you”, whether that traffic is destined for one of their customers (someone on Comcast scrolling Instagram), or they’re just providing the link to the next major node (Comcast being the link between AT&T’s segment of the US backbone and Big Mike’s Internet out in podunk Nebraska).
And normally that works pretty well, until power users start moving huge amounts of data and unbalancing the traffic.
That depends on where those bytes go, though. There is also the concept of “settlement-free peering” and content caches that are located in the ISP network.
For example we have a Google Global Cache instance in our network, so most Google traffic is served from there and we don’t pay anyone per byte, we only pay for the power and space. Same for Akamai. Then for Microsoft, Cloudflare and Facebook we have peering links, where we can send and receive data related to their services freely, without balance requirements.
Of course this is only possible for larger networks (peering with everyone is not feasible) and we still pay for the other traffic, but it takes care of a lot of the volume.
ISP shittiness aside, ISPs do actually pay for Internet backbone access by the byte. Usually there are peering agreements saying “you take 1tb of traffic from us, and we’ll take 1tb of traffic from you”, whether that traffic is destined for one of their customers (someone on Comcast scrolling Instagram), or they’re just providing the link to the next major node (Comcast being the link between AT&T’s segment of the US backbone and Big Mike’s Internet out in podunk Nebraska).
And normally that works pretty well, until power users start moving huge amounts of data and unbalancing the traffic.
That depends on where those bytes go, though. There is also the concept of “settlement-free peering” and content caches that are located in the ISP network.
For example we have a Google Global Cache instance in our network, so most Google traffic is served from there and we don’t pay anyone per byte, we only pay for the power and space. Same for Akamai. Then for Microsoft, Cloudflare and Facebook we have peering links, where we can send and receive data related to their services freely, without balance requirements.
Of course this is only possible for larger networks (peering with everyone is not feasible) and we still pay for the other traffic, but it takes care of a lot of the volume.