I'm actually not sure that a large mall is a great fit for a supercharger, unless it just has unused parking lot space it wants to monetize (assuming Tesla even pays rent).
It seems like a convenience store or grocery store is a much better fit. Charging is a 20-40min stop. You don't want the charger to be super-close to the front of the lot otherwise it gets ICEd, so for something like KoP you'd spend half your charging time walking to/from the entrance, and what are you going to do in a mall for 10-20min?
For a grocery store the lot is much smaller, and you can just run in and get snacks/etc.
There just isn't the same synergy for a mall, so while it costs something to set up and maintain, it doesn't actually generate much business. Unless somebody wants to charge for 20min and wait in the car, then go re-park and shop.