Thats the hurdle. Netjets no doubt racked up huge losses in positioning costs before the critical mass of a client base was met (a loss-leading process they are probably facing again as they try and break into Europe).
Zillionaire backing does help with this process I spose, but certainly in the UK there does not seem a large enough client base to achieve this with Helos on its own.
It would be interesting to know if a scheme would work in the States though - or maybe offer it here on cheaper machines for a wider market.
Hmm.. fractional ownership.. would that make the flight category private rather than public transport??