[bobfunk]

We provide both SNI based SSL (starting at $9 including the cert) and full SSL ($49) with CDN based hosting at https://www.netlify.com

As many other has noted, even when once in the future you'll be able to rely on free certificates from Let's Encrypt, serving millions of sites with different certificates (that needs to be replaced every 90 days) adds lots of complexity to any CDN based infrastructure and cost real money.

Apart from that, if you do just SNI based SSL you have to add support costs for explaining to people that don't know the implications, why things like some automation tools, old Android browsers, IE on Windows XP, etc, breaks.

And if you do full SSL you need to allocate lots of IP addresses at each CDN PoP which is expensive.

The certificate is just a small part of the equation when you're offering CDN based SSL.