I see inflight duty free as a way to suck more money from passengers - nothing more.
Giving bonus points on QF for inflight purchases is probably just a way to scam the consumer into buying it there and then rather than wait til they get to the airport [creating a sense of urgency & incentive to the customer i think its called? ;]
Also other airlines, like AA for example have heaps of things you can "buy", not just inflight. It's more like a spam session.
If you really wanted the extra X points, put it on your ANZ QF card and get double points (til oct 31)!!
