As I've posted many times before all they need to do is like SouthWest in the USA (easily most profitable airline in the USA) and offer a free flight for each 10 paid flights.
As bran-e mentioned before, not a bad idea. However, let's look at it this way.....
- Person A travels on mainly 'Happy Hour' or 'Sale Fare' between MEL-SYD-MEL 5 time a year. Total costs: approx $600 ($118X5 based on Happy Hour fares).
- Person B on the other hand, travels for business on the above mentioned route and frequency BUT on he 'Blue Plus' or 'Flexi Saver'. Total costs approx $2300 ($229X2X5 based on 'Blue Plus' fares).
It seems to me that perhaps that Person A would be the greater benefitor of this FF scheme if is based on the 'fly-10-get-1-free' idea. Naturally, I know that companies might pay for business travels (Person B) and the ultimate benefitor would be Person B him/herself anyway, but from this perspective, it would be odd from DJ's view in terms of revenue/profit that they could generate.
Just my 2 cents.