An exponential works in an unlimited population or for as long as it's effects are negligible compared to total population size. Once you have converted a signi

An exponential works in an unlimited population or for as long as it's effects are negligible compared to total population size. Once you have converted a significant part of the population, the number of possible targets starts to drop exponentially. You will reach for the highest hanging fruits, sysadmins who don't give a crap, nutcases that hate IPv6 for killing their dog, legacy devices that only Bob knew how to manage but we fired Bob back in '98, and so on. There's every reason to believe reaching a point where IPv6 is widely enough supported to allow you to turn off your IPv4 address, say over 99%, will take the same number of decades as has taken to get to 50%. You can already see this reverse inflexion in countries that are further along like US and Germany.