I appear to be in the minority here but I think that it's immoral for a gliding club to expect an "outsider" to fly the tug for free. After all, the club charge for a launch yet keep all the profits for themselves.
Bidford, for example, are doing the decent thing - you are more likely to get a loyal, professional performance from your tug pilot if you reward him for his efforts.
I appreciate that the flying is free - but to expect the tug driver to work for nothing stinks. It's almost as bad as Ryanair!