The difference, avek00, is that in the examples you cite, the outcome (the FF miles) was basically guaranteed. A rational decision could be made as to whether $X for pudding would be worth X FF miles.
This promotion is far more akin to gambling. Unless you have an incredibly magnanimous employer or rich uncle picking up the tab for 3x/weekly flights to Europe, etc. you could end up spending thousands and thousands of dollars for a prize of ($? - I haven't bothered trying to estimate) value that you might not even win.
But yes, nevertheless, there are bound to be people that will take this to mind-blowing heights.
[This message has been edited by bokich (edited 12-12-2001).]