United Airlines recently added the feature for Mileage Plus members to purchase an additional 1,000 miles on upcoming roundtrip flights for a fee of $20. So, in addition to the miles you earn with your flight, they are letting you tack on a few extras. Registration in advance of your flight is required.
Terms and Conditions
As you are a valued United® Mileage Plus member, we are pleased to offer you a special opportunity: Receive an extra 1,000 bonus miles on your next United roundtrip for just $20. Simply register and pay $20, and your account will be credited with 1,000 bonus miles after your next paid, qualifying flight on United, United Express® or TedSM.
Registration is required prior to travel for each qualifying roundtrip completed before December 31, 2008. There is no limit to the number of bonuses you can earn, though only one bonus can be applied per roundtrip. The registration fee is $20 per bonus.
Members must register for this offer at united.com/addmiles between January 1, 2008 and December 31, 2008. Valid credit card will be billed immediately for the registration fee. Registration fees are non-refundable and are subject to change. Prices are quoted in USD and include applicable federal excise tax. Roundtrip is required. A roundtrip is defined as travel from an origin city to a destination city with return travel beginning in the outbound destination city back to the first origin city with all segments on United, United Express or Ted. Open jaw and circle trips do not qualify. Valid only on paid, qualifying roundtrips completed between January 1, 2008 and December 31, 2008. Members will earn 1,000 bonus miles on the first qualifying roundtrip originating and completed after offer registration. Valid only on flights operated by United, United Express or Ted and not on United-marketed code share flights operated by other carriers. Offer is combinable with other bonus mile offers. This bonus may be earned a maximum of one time per qualifying roundtrip. Members may register to earn this bonus an unlimited number of times for qualifying roundtrips completed by December 31, 2008. The registration fee is $20 per bonus. Must be a Mileage Plus member to participate in this offer. Miles for the completed qualifying flight must be posted to the Mileage Plus account in order to qualify for this bonus. Allow 1-2 weeks after your flight posts to your account for the bonus miles to be applied. Bonus miles do not count toward elite qualification. All standard Mileage Plus rules and conditions apply. Miles accrued, awards issued and bonus offers are subject to the rules of the United Mileage Plus program. The Mileage Plus program, including accruals, awards and bonus miles offers, is subject to change without notice. Offer subject to change without notice. Other restrictions may apply. United and Mileage Plus are registered service marks. For complete details about the Mileage Plus program, visit www.united.com (MPD038)
This seems like a reasonable cost for miles ($0.02/mile) which is about market value of a mile. However, the miles do NOT count toward Elite Qualification.
This might also be viewed as a way for the airlines to capture more revenue from the consumer while further de-valuing the miles you accrue through actual flights.