I left a shop with more than 3000 items EACH on 17 tables and 28 racks for less than 20 minutes to grab some stuff and then got in bed to do the rounds with neighbors. When I reopened the game it flashed that I had earned over 300k. Many racks were then empty and everything else is left no more than a few hundred items.

Sorry. This deserves to be spelled, not an acronym. What the hell?