I filled out a very quick survey after getting an email from US Airways Dividend Miles Dining program. Of course, this is run by a third party that runs similar programs for other airlines. Interesting how they figure out the value of a mile. Also interesting that they figure Mileage Plus miles are worth nearly twice as much as Dividend Miles.

Here's a copy and paste from their site:

No purchase necessary. Void where prohibited. Official rules are available here. The sweepstakes is sponsored by Rewards Network Establishment Services Inc. There are four prizes, and each prize is either 2,500 Dividend Miles ($65 value), 2,500 Mileage PlusŪ miles ($125 value) or 2,400 Rapid Rewards points ($60 value). The form of prize will correspond to the program in which a winner is enrolled. The odds of winning depend on the number of valid entries received. The Sweepstakes ends on March 11, 2011. Only open to respondents who are legal U.S. residents, 18 years of age or older, who received a link via email to a survey from Sponsor regarding ratings and reviews feedback and who complete and submit the survey.