Customers love contests. Whenever there's contest, there's bound to be an extra purchase. For example, the Drypers contest. They need to purchase at least RM40 to entitle for the contest. At first they bought less than RM40. But after explanation from the shopkeepers, they would buy extra to top up to RM40.
To participate in more contests, hop over to http://www.facebook.com/ChangJiangEnt. There are many contests awaiting the customers.