[phicoh]

If you assume that IPv6 adoption is only due to IPv4 address shortage, then the rate of adoption makes a lot of sense. Whatever alternative to IPv6 you can come up with, as long as there is plenty of IPv4 space, nothing will happen. Unless you can find a killer app in a different area, which hasn't happened.

Now that you have to buy IPv4 addresses at around $10 for a single address, the game has changed.

With carrier grade NAT, content has to slowly migrate to IPv6 for geo-location reasons. Any content that sees a high amount of abuse also has to avoid CGN.

Once big parties like google, facebook, etc. have a lot of traffic on IPv6, it stops making sense for them to invest in IPv4. So they will try to pressure ISPs into offering IPv6. Likewise, if an ISP sees that big content providers are on IPv6, then it stops making sense to invest in IPv4. Pressuring smaller content providers to offer IPv6.

And then IPv4 joins the ranks of IPX, NetBIOS, Apple Talk. Some pockets may continue to exists, but the rest of the world has moved on.