Adopting IPv6 is much much harder. The problem with IPv6 is that it needs to be everywhere at once before it is useable, while protocol like http can be deploy

Adopting IPv6 is much much harder. The problem with IPv6 is that it needs to be everywhere at once before it is useable, while protocol like http can be deployed incrementally and can coexist just fine with other protocols[1] [1] http://gumuskaya.com/images/tcp-ip.jpg http://gumuskaya.com/images/tcp-ip.jpg