Just an update for those who were watching this, and it's a lesson for all of us.
I finally got access in to the Google Analytics for our site (did it in a not so kosher way, but at least I got them), and sure enough I found major 'bot' traffic that was being passed along as the real deal. After fighting to get it removed (the ad company swore up, down, left, and right that it was legit traffic - despite the clear-cut evidence to the contrary) sure enough for June our traffic was down 10% yoy, which helps to explain some, but not all, of the reduction in submissions.
There are politics of the situation that prevent the store from moving to the next logical step and ending the relationship with that agency. But at least everyone knows that I have a clue as to what is going on and these folks will have to 100% toe the line going forward, because they know someone with knowledge is watching them.
