Meanwhile I did some checking. I found that the website is [
www.azsecretshops.com] It was originally set up in November 2003 and the domain expires November 2011. The address on the website matches the address of the registration (that is a good sign). The website has a toll free phone number. When I tried a reverse lookup on it, the results told me it was an "invalid phone number". When I googled the number I found a number of hits with an apartment newsletter, the most recent from Nov 2010, as a service provider to landlords for secret shops, in most cases followed by an EPMS listing.
Overall my assumption is that this is a very small company, probably fully legitimate, that does apartment shops in a very restricted area of Arizona. If you happen to live near Gold Canyon, AZ, it probably makes sense to investigate further by picking up the phone and calling them.