Airport officials say the revenue goes back into airport operations. The money reduces the landing fees paid by airlines, ultimately resulting in lower fares for airline passengers.
In 2009, the first full year of operation, the valet service parked just 2,600 cars. Today, it's a 24-hour operation.
The airport says the operation has grown on average about 37 percent a year, thanks to its popularity among business people. The service is operated by a private company, but the airport gets a share of the revenue.