AW have been extremely smart in marketing to the thriving lease market (e.g.
LCI,
MAG &
Waypoint). The company has structured its cross-fleet sales deals so that the lessors can enjoy significant flexibility in which aircraft they actually end up taking -- for example, an agreement is made to buy $100M of 139s, 169s and 189s, but the actual ratio of models taken is left negotiable until end-user customers are secured.
I'm sure the success of the 139 has also helped its bigger brother!
I/C