Private jets are becoming more and more popular everyday. Private jet rentals are very expensive and a lot of people do not consider private jet rentals as cost effective. However, the cost effectiveness of private jet rentals (or anything for that matter) cannot be judged in absolute terms. It has to be considered on a relative basis.
The key thing here is to determine the value of your time and then compare it with the cost of private jet rentals. Again, this has to be considered not just in terms of the time you are saving by avoiding queues or by avoiding multiple security checks but also in terms of the time you are saving by proactively preventing the backache or tiredness caused by other normal flights.
Any kind of stress or tiredness prevented by use of private jet rentals is also your gain in terms of saving your next day or next few hours. Moreover, a super comfortable flight (through private jet rentals) can increase your work efficiency (or make your family vacation even more effective for you).
When it comes to business use of private jet rentals, the justifications go even beyond the value of time. In business, speed can sometimes create the difference between you getting a deal and losing a deal. With private jet rentals, you are no more dependent on flight schedules. You are the boss and you decide the flight schedules as per your needs. Sometimes you might be working on two or more deals at the same time which requires you (or your best sales person) to quickly move from one place to another. In such cases, you can forego the dependency on airline flights and use private jet rentals to move quickly from one place to another.
So, there are a lot of benefits associated with private jet rentals. However, these benefits have to be looked into from the perspective of the value of your time. For a lot of people, private jet rentals are in fact very cost effective.