“A jet card is cheaper than chartering.”
A jet card is prepaid flying: you deposit, say, $150,000–$250,000 with a provider (NetJets, Flexjet, Wheels Up, VistaJet and dozens of brokers), and draw down at a fixed hourly rate for a given aircraft category. Light-jet cards in the US run roughly $7,000–$10,000 per hour once taxes and fuel surcharges are included; super-midsize around $12,000–$16,000.
On-demand charter for the same aircraft, quoted trip by trip, can be $5,000–$8,000 per hour for a light jet — but that's before repositioning legs, minimum daily charges, overnight fees and peak-day surcharges, and it assumes an aircraft is available. On a holiday weekend it may not be, or the price may double.
The card's fixed rate means the provider absorbs the repositioning cost and the peak-day risk (though most cards now have peak-day surcharges and longer notice periods of their own). It also means you pay for hours you might not use, with expiry dates and 'daily minimums' that round short flights up.
The honest rule of thumb from industry analysts: cards for frequent, spontaneous, one-way flyers; charter for planners and round-trippers; fractional shares above about 50 hours a year.
Sources: privatejetcardcomparisons.com · en.wikipedia.org