Yep, it was the advertising bit I was/am worried about. Like all things aviation it's about line drawing, and I reckon that posting to an international anonymous forum falls the wrong side of it.
On the other thing, it's the *direct* costs of the flight which can be shared. A/c hire, fuel used, landing fees, batteries in the GPS, 3 mms of chinagraph pencil. Hangarage, insurance, epaulette ironing fees cannot be shared (you'd be paying these costs even if you didn't fly). If I remember correctly, the pilot has to pay a minimum of 25% of the direct costs as well - so in a six seater the other 5 are only allowed to contribute 15% each of the direct costs.
Here's one: If you get the weather on Saturday (extremely unlikely, even though I haven't booked our a/c, which normally ensure CAVOK), are you going to keep the fuel drawback yourself? I reckon, even if you have to wait a few weeks, this should count against the direct costs. In our machine, I can get 66 fuel drawback refunded, and to and from L2K for about 60 quid rental + 10 quid landing. Thus the trip costs 70 quid, with a 66 quid refund - the direct cost is 4 pounds (a quid each)!!!!!!
SteveR