United MileagePlus miles are customer reward miles that the program's members earn by traveling on a United Flight or through the airline's various partners. Some of the partners that allow MileagePlus members to earn miles include the Hilton hotel, Hertz car rental, Amtrak rail service and United Cruises.
Other methods of accumulating MileagePlus miles include shopping at any of the program's 850 partner retailers, including Best Buy and Nordstrom. United MileagePlus members can use their accumulated program miles to access award travels or upgrade their seat on a United Airlines flight. The program's miles can also be used for shopping, dining, cruise awards and hotel awards.