Email has it. Git has it.
I can see a self hosted HTTP gateway with Durin being very useful.
Was chatting with players of the niche open-source AssaultCube computer game, and turns out they have a not-so-great solution for custom map textures/models. Was thinking of dropping in an IPFS client for them.
My benchmark for this is sharing a file using the standard IPFS application and then trying to download it through either ipfs.io or Cloudflare's IPFS resolver. It usually took me about two or three timeouts before the file finally appeared and stayed available for a while. Direct IPFS to IPFS transfers using IPFS apps on both sides didn't seem to work well.
The daemons also seemed real CPU heavy for some reason.
It's a real shame, because I like the concept of the protocol. Maybe this approach of using an external, optimized pinning service wolves these problems, but that doesn't align with the goal of IPFS of course.