The reasons for IPv6 should be obvious by now, most importantly you are future proofing your service/product. Saying I don't need to deploy IPv6 is the same mentality that kept the world using Internet Explorer 6 for over half a decade, yes it works as is but it could be better.
Plus do you want to live in a world where something as basic as an IP address costs you an annual fee?
You'll also provide a faster service ahead of your competition:
To be honest, IPv6 isn't exactly hard for a lot of project. As buyers we just have to add it as a purchasing requirement. The real burden is on the ISPs and cloud providers.
that link is dead (403 - forbidden) but seems to address the differences between ipv4 and ipv6.
he was asking why you'd need ipv6 support for a CDN, which is mostly hosted by other people. you only reference it in your html code, once. so his question would probably still be unanswered, even if your link worked.
Plus do you want to live in a world where something as basic as an IP address costs you an annual fee?
You'll also provide a faster service ahead of your competition:
http://www.internetsociety.org/deploy360/blog/2015/04/facebo...
http://www.computerworld.com/article/2983996/internet/ipv6-w...
To be honest, IPv6 isn't exactly hard for a lot of project. As buyers we just have to add it as a purchasing requirement. The real burden is on the ISPs and cloud providers.