You may not like to spoil your staff too much and there is a chance too much luxury will go to their heads but there is a lot to be said for letting your top people travel by private jet sometimes. Regardless of how much they value it it can create instant value for you if they are arriving at meetings having had time to relax, prepare and even sleep. You also don’t want vital members of staff stuck in airports for hours waiting for flights and then waiting for baggage at the other end: for international travel the time wasted is even worse. With a private jet a two-hour meeting or a quick visit to a trade show could be done in a morning or an afternoon, with commercial air travel it could end up being an overnight stay.
There is of course also the fact that staff value being able to enjoy a luxury flight on a private jet, you may want them to be getting some work done but it is still enjoyable and something other staff will aspire too. This means travel in private jets will make staff more likely to stay with your company and more satisfied and will keep other staff inspired to reach the level where they get the same benefit.