(2) limited time special effect.Although limited-time special offers make consumers very excited, but such promotional activities are obviously not every day. When carrying out this kind of promotion, supermarkets often adopt the method of direct use of live notice broadcast in the store, whose publicity scope is only in the selling area, and only the consumers in the selling area have the opportunity to participate. Although this kind of promotion has obvious effect, its influence scope is limited. According to the word of mouth effect, even if the consumers involved in the promotion later publicize the event to others, the promotion is after the event, with a certain time lag. Therefore, although the promotion of limited-time special prices can be immediately effective, but its effectiveness and promotion capacity is always very limited.