I believe at the time they deployed their Universal SSL, which was over four years ago, is absolutely massive scale, and is free, they were the partner that cou

I believe at the time they deployed their Universal SSL, which was over four years ago, is absolutely massive scale, and is free, they were the partner that could actually deliver the necessary integration and infrastructure to handle that sort of load. Also, they were amongst the only ones to offer ECDSA certificates IIRC. Cloudflare detailed a little bit about this in this and other blog posts: https://blog.cloudflare.com/universal-ssl-how-it-scales/ https://blog.cloudflare.com/universal-ssl-how-it-scales/