I love these guys. Because of the types of evaluations they do of behaviors, their shops always seem a little kinky, but kinky can be fun :-) They pay well, they pay promptly and they are intelligent to deal with. I could ask for little more from any company.
Sales pitch over, it breaks my heart that they don't have more in my area. I have done shops that were a one time evaluation of a location or locations. It means that prep time for the shop is often used only for one or a couple of shops. That seems to be a reasonable reason for the higher pay.
Their shops have ranged from fairly standard retail evaluations to integrity shops to dumpster diving for documents with customer information that has not properly been destroyed to evaluating compliance with safety and loss prevention standards. A little variety in your 'diet' of shops.