Southwest sues people who monetize this kind of product -- see a 2012 example at http://www.bizjournals.com/dallas/news/2012/03/02/Southwest-... or a 2007 example at http://www.internetlibrary.com/cases/lib_case511.cfm.
http://www.southwest.com/flight/early-bird-retrieve-reservat...
Southwest Airlines automatically reserves a boarding pass for A-List Members beginning 36 hours prior to scheduled departure of the Member's confirmed Southwest Airlines flight.
"You may not use Southwest's sites for or in connection with offering any third party product or service not authorized or approved by Southwest. For example, online check-in service providers may not use Southwest web pages to check-in Customers online or attempt to obtain for them a boarding pass in any certain boarding group."
http://www.southwest.com/html/about-southwest/terms-and-cond...
Which sucks, because your product looks really cool. (And I'd forego paying $10 to use your service... which is probably why it's banned. :P)