Customers Not Cargo Act of 2017 This bill requires the Department of Transportation (DOT) to revise regulations to: prohibit an air carrier from forcibly removing a passenger from an aircraft after boarding because the carrier oversold the flight or to provide a passenger seat to an employee of the carrier; establish standards for resolving oversales once an aircraft has been boarded through escalating incentives to passengers to encourage voluntary rebooking; and require an air carrier, to the extent practicable, to resolve issues related to overselling a flight before boarding the flight. DOT shall consider providing exceptions in such regulations for a medical emergency or a circumstance that poses a threat to the safety of the flight.