In this case, you should have a set of machines, a cash register that can swipe your card. First, calculate the gross profit of the product. If your product can make a gross profit of 51%, you can choose to give 51 for 11, which gives people the impression that it is 51% off, but in fact it is only 66% off. Moreover, you should make time-limited purchases, such as 3: 11 pm to 4: 11 pm, 9: 11 pm and leisure time.