Mel_traveller, I am not sure I understand what you mean by "given the fare paid" and the relation to $70. A return PEY SALE ticket on QF (as I had) costs $3,600 USD return SCL-SYD. (They are $4,400 full fare, but I got mine on a sale) So that is $1,800 USD each way for me, so $2,340 Aussie dollars for this one sector. $70 compo equates to 3% of the fare.
Forgive me, but I rate IFE far more than 3% of the fare, especially when in the situation of being in a locked metal tube for 12hrs+
And to me an important point about compensation in such situations is that IT IS NOT ABOUT MISSING OUT on the movie service. It is about being trapped where you no longer can seek this service elsewhere. A long haul flight for me is MISERABLE without IFE. I would not willingly book that QF PEY flight if I knew there would be no IFE - I would not even pay half the fare - I would NOT travel!
Compo should make reasonable amends. IMHO it is not (and should not be) a concept equivalent to a simple refund for a service or part of a service that was not provided. It is a concept of trying to repair the pain and suffering (disappointment / etc) that the pax felt.