[ppml] early adopter advantage

# It would however make it easier for providers to start working with their
# smaller multi-homed customers on adoption.

in terms of marketing, the obvious first customers for IPv6 are those who are
already multihoming with IPv4.  this preselection is due to the need for an
ASN, routers, BGP, and higher basic understanding.  if we want to know why V6
growth is even flatter than the most pessimistic projections of five years ago
we need look no further than "let's disenfranchise the users most capable of
being our early adopters" as the somewhat odd reason for it.