MusicMan...this survey was sent out by Delta Advisory Panel. Learn more at http://www.deltaadvisorypanel.com

Taken from the FAQ section of the site:

How can someone join the Delta Advisory Panel?
First, you must be a SkyMiles member that has enrolled in Delta's E-mail Programs and selected to receive Delta surveys and research information. Second, from this group, a broad range of people with access to the Internet and an e-mail account will be sent an e-mail invitation to join the panel and complete a short initial survey. This survey will ask several questions about the potential panelist and the services used. We'll then use this information to determine which members are invited to participate in which surveys. All information provided is private and will not be shared. See the Privacy Statement for details.

Can I refer a friend or colleague for membership in the panel?
No, panelists are selected by invitation only. However, from time to time we will recruit new members. So, if you know someone interested in joining the panel, invite them to enroll in the Delta SkyMiles Program, sign up for E-mail Programs, and select to receive Delta surveys and research information.

Hope this helps

Andrew