I am totally against illegal charter, but while we are discussing hypotheticals
...
The purpose of the law is to prevent you running something that is like a passenger service, with the schedule set out in advance. Read the ANO with this in mind.
Indeed but nobody can do that unless they
massively breach the cost sharing rules, because no pilot is going to do the flight unless they can make a
profit.
Sophistry about websites being premises, or a closed group of (passenger) friends being a flying club, is not worth bothering with. I looked into this type of approach when advising on an internet lottery in 1995, and took the view that no court was likely to be impressed!
17 years is an awful awful long time. The internet was virtually unknown in 1995. In fact my business (going since 1991, though I have been in business since 1978) only started sorting out a website in 1995!
There are good reasons for a CPL being a step beyond a PPL and more good reasons if it becomes a commercial op to meet the AOC requirements
Indeed, but a CPL is almost worthless. Anybody can get a CPL. The JAA CPL is "just" 9 exams plus a really picky VFR dead reckoning exercise which has to be done via an FTO (though it can be done outside JAA-land). What the CAA actually goes for is the AOC; that is what costs the real money, and is supposed to keep the cowboys away from charter work.
As I said above, the argument is really why it is illegal to advertise a cost shared flight on a club website, but is legal to advertise the exact same flight on a notice board in a decrepit wooden hut with water coming in through the roof?
How about having the said wooden hut, with a notice board on the wall, and a projector shining onto the noticeboard, and the projector being connected to a PC running an RDP server, and having a webcam monitoring the noticeboard, with the webcam having an HTTP server. Then you meet the requirement of the "club premises". The law doesn't say the advertised cost-shared flight has to be viewable only by a physical human presence in the physical premises.
I think the present drafting was the best the CAA could hack together, many years ago and long before the internet, to make it reasonably hard to set up cost sharing arrangements.