Last week Southwest launched a promotion for Colorado residents, whereby those that sign up for a Rapid Rewards account get one free ticket for every roundtrip Business Select ticket they book to/from Denver by January 31 for travel through February 28.

United has sort of matched, although not surprisingly you need to be a lawyer to understand the terms and conditions. All the details can be found here and registration is required. Basically you get an electronic certificate good for a free ticket for every roundtrip economy ticket booked in “Q” class or above by February 14 with travel completed by March 5 (that’s right, if you actually pay for first class you don’t qualify). Only those with addresses in Colorado and travel originating in Aspen, Colorado Springs, Denver, Durango, Eagle, Hayden, Grand Junction, Gunnison and Montrose qualify. “L” class availability is required to redeem the free ticket, which can be tough to come by on some routes.