I found this on another site and the author makes a good point.
"Well in a strict sense the "program launch customers" are the airlines
who order enough planes to fulfill the minimum order requirement,
regardless of when they get their planes, e.g. Lufthansa ordering
enough 737s to allow Boeing to build it, or PanAm ordering 21 747s. In
this sense Both SQ, EK, QF etc are all "launch customers" of the A380,
while Singapore is the "launch operator" (my own term) in the sense it
will be the first to put the plane into revenue service.
ANA will be both a program launch customer and the launch operator of
the 787.
Air New Zealand, the second ever 787 customer, will only get its first
plane in 2010, the first 787-9. So in this sense ANZ is a "program
launch customer" as well as a "model launch customer" even though
first delivery is 2010, 2 years after first 787-8 delivery.
Sometimes, due to politics or other factors, the actual launch
customer is not advertised as such; the hot selling 777-300ER is a
classic example, with Air France as the actual launch customer, but
JAL was the "advertised" launch customer. Air France was first to
order and first to fly the 77W.
You find all sorts of launch customers, some more marketing spin than
others, e.g. "African launch customer" or "North American launch
customer" as well as "GE launch customer" or "RR launch customer" for
various engine\airframe combinations.
A hard and fast rule is:
1) whoever orders before official program launch ("the ones who make
the program possible")
2) whoever orders a special variant of the base model and makes that
variant possible (787-9, 787-3, 787-10, A380-900, B777-300ER)
3) whoever orders enough of a specific engine\airframe combination to
allow the engine program to go ahead can be considered that
powerplant's launch customer."
