[est31]

Is that with at least some attempt at building a CDN? Generally cloud providers don't charge for traffic between hosts in the same availability zone. One could think about putting a slave into each major availability zone of various cloud providers. The main service would then only be used to create HTTP redirects to the specific slave, or if none exists, or the package isn't replicated yet at the slave, just answer directly.

Even if such a system isn't built, with that kind of money on the table you could get a team of FANG scale developers to build it for you.