Sorry if I came across grumpy but I still can't believe you didn't cover this at PPL. Perhaps you didn't use the Trevor Thom books because, having just referred to my mate Trev chapter 10, he also tells me that no more than four persons must be carried and that the pilot must not be employed by the operator in addition to the advertising rule.
If you go round all your friends and family and put it to them as a proposition, then it does help to defray the cost of hour building.
The only problem with the "flying club thing", is that, because there are so fewer helicopter pilots, there is less chance that people will take you up on your offer since all the members of any heli-school's club, can already fly themselves and, no doubt would also want to log PiC time!
Cheers
Whirls