Yep. This high level stat reflects EVERYTHING.
#1). Overall Market conditions (spooked shoppers in 2008 vs "Leasing is back!" in 2014).
#2). All of your OEM's efforts (fresh products, marketing to drive traffic, incentives to convert)
#3). All of your OEM competition's efforts (fresh products, marketing to drive traffic, incentives to convert)
#4). All classified shopping sites ability to replace the need to visit to your website.
#5). All of your dealership efforts (right product mix, marketing to drive traffic, your sales teams ability to convert)
#6). All of your retail competitor's efforts (right product mix, marketing to drive traffic, their teams ability to convert)
#7). Your svc. dept's traffic.
Caution!! Once you try to look across rooftops & compare (like Stefan and Bill's examples), it's bad practice to rank stores against each other because you need to factor in more variables. A few are "distance from major market", # of cars that drive by, competition (all), inventory profiles, franchise shopper behavior (i.e. jaguar = lots of wanna be shoppers) and on and on...
HTH
Joe