I'm still not entirely convinced that serving apps closer to users solves more problems than it creates, but I am always impressed by the fly.io blog posts. The writing style makes them a joy to read.
It was an interesting decision to make a SaaS out of this solution, though, as I think 99% of problems are not solved by having machines closer to their users.
Most of the big operators have peering agreements in place, but that doesn't mean every participant has infinite bandwidth. Google Global Cache and Netflix Open Appliance go a long way to reducing costs by avoiding interconnect where possible.
My guess is the cost differences are still there, but the increases in capicity and decreases in all costs combined with the difficulty of users to control traffic at that level mean that you would really only see this if you're buying a lot of transit. If you're just a residential customer, it might be more likely to impact you as your ISP may have more congestion on oceanic routes rather than an explicit charge.
I do occassionally see hosting operators that will optionally charge more for access to some routes that are better but too costly to include in a bundled rate.
It’s also pretty common for people running large LAN parties to run a local Steam cache so that when everyone in the building decides to download a game on the list of tournaments it’s coming over the local network rather than downloading hundreds of copies from the Internet.
Fly.io fits that latter category perfectly. Global distribution was generally Too Hard to consider for my projects. Now it isn't.
Well said.