Posted by a Sony owner earlier in 2015 http://www.dpreview.com/forums/post/55768074
Sony themselves say explicity:
Membership Requirements
Qualifying applicants must meet all of the following requirements:
- Owns a minimum of 2 Sony Alpha Full-Frame interchangeable lens Cameras and a minimum of 3 Sony ZEISS(R) and/or G Series lenses
- Be an active professional photographer (self-employed or an employee of a professional imaging business/organization).
- Provides professional work samples - either tear sheets or a business URL with galleries.
- Provides Membership Fee Payment.
- Has received an invitation from Sony Electronics to join the program.
- Has reviewed and agreed to the Terms & Conditions
Maybe in view of the shakey support provided in the US, they want to invite you so they are not overwhelmed with too large a volume of DHL air freight packages back to Japan for repair?

And the Marketing Department wants to LEARN of the few professionals using Sony dSLRs?!

Sony commanded the professional video camera industry with the Betacam lineup, I wonder why they cannot rely upon that servicing network for its professional cameras (leaving Precision for the amateur lineup)