In February 2011, the global Internet Assigned Numbers Authority (IANA) allocated the last blocks of IPv4 address space to the five regional Internet registries. At the time, experts warned that within months all available IPv4 addresses in the world would be distributed to ISPs.
Soon after that, unless everyone upgraded to IPv6, the world would be facing a crisis that would hamper Internet connectivity for everyone. That crisis would be exacerbated by the skyrocketing demand for IP addresses due to a variety of factors: the Internet of Things (refrigerators needing their own IP address); wearables (watches and glasses demanding connectivity); BYOD (the explosion of mobile devices allowed to connect to the corporate network); and the increase in smartphone use in developing countries.