At first you had to be an heir to share. In 1986, Goldman Sachs executive Richard Santulli took an algorithmic approach to create fractional jet ownership. His company, NetJets, expanded the private-jet market from the obscenely rich to the merely filthy rich by dropping the price of ownership from $20 million-ish to less than $2 million. Fifteen years later, Kenny Dichter doubled the market size again by selling a Starbucks-like Marquis card that allowed the garden-variety rich to spend a mere $160,000 or so to purchase a set number of private-jet hours.
Now Dichter and other private-jet-biz veterans are lowering the...