there's also the IP Anycast [1] option. That's what you get with OVH CDN [2], for example, but not with CloudFront. Anycast routing is totally independent from DNS, thus it works fine with an A record and also makes it easy to install SSL certificates.
This is actually a great point against using custom domains (CNAMEs) with Cloudfront. At least if you can't afford the custom SSL certficate option.
Cloudflare somehow got this right. They serve non HTTPS enabled web sites with different IP addresses so that you can never reach them over HTTPS (could be better "This webpage is not available" vs. scary red "This is probably not the site you are looking for!" message in Chrome). Plus, they have a great free anycast DNS network that can be compared to Route 53. And best off all, you never pay for the bandwidth.
That's what I immediately thought when I first read it, especially now that Github Pages are served over Fastly's CDN [1].
Then I realized that Github Pages do not support server side (301) redirects at all. Quite a big turn-off when you move an existing website over a new platform.
definitely not doing Anycast. As I wrote just a few days ago [1] github.map.fastly.net resolves to a different IP address based on the geographic location of the user. The exact server location might be approximated from the X-Served-By response header:
That's a good point I didn't consider.