The Champs are working on a set of National Landmark Guidelines which should be up for comments from general users sometime tomorrow...
Parking Lot landmarks do NOT suppress traffic jams (there was a long discussion [read: arguement] and several Waze staffers were also involved to confirm this), however, they do suppress Off Road MPs.
In my opinion giving someone verbal instructions to turn left at 7-Eleven is a lot different than seeing 7-Eleven on the map... If they are using Waze, why would they be told to turn at 7-Eleven anyway? They would be told to turn at <Road> in <Distance> which is more valuable.
P.S. If you have any specific questions about the CT Guidelines, PM me...
Re: Landmarks - Missouri Wiki update discussion