However, I think the popularity of these clubs are on the decline for one simple reason: private jets now have enough range to fly almost anywhere in the world with just one fuel stop.
When you have modern executive jets with a range of over 5,700 nautical miles and with Boeing and Airbus producing private jet versions of the 737-700 and A319, famous people can fly anywhere without the hassles of commercial airline terminals or be tied to commerical airline schedules. I mean think about it. You're famous movie star Mel Gibson, and you want to go from California to Australia to visit your old time friends; Mr. Gibson has enough money that he could contact Executive Jets and get access to fly him and his entourage to Australia on a Gulfstream V with only one fuel stop in Hawaii.
(Then of course there are celebrities like John Travolta, who owns a 707-138B with an extremely well-equipped interior.