there seem to be some shops/places that the customers stay longer in, like the food, jewelry, and the mini mart. i put the food and the mini mart in the beginning at the later levels, and put the jewelry somewhere in the middle. this helps slow the customers down a bit. it is also important to build up your property on the right so that when the customers get there they have a better chance of getting in a store to use the rest of their money.
 "Shopping Street"){kind=icon}
 "Mastermind: World Conquerer"){kind=icon}