As Chinese Lunar New Year draws near, a busy yet happy period of "grabbing red packets" on smart phones is coming too. The 2015 Spring Festival marked the coming of digital red packets on WeChat. During that Lunar New Year, for the first time, many Chinese people started to use red packets on their WeChat to express their best New Year wishes to others. And "grabbing red packets" also became an extremely popular game on WeChat. As people establish a series of groups among their contacts on WeChat, during special festivals, such as Lunar New Year, someone will distribute a certain numbers of red packets in a group, and other members will try their best to grab one red packet. Often other members will follow and go on distributing more red packets. The money in each packet is random, from 0.01 yuan ($0.001) to less than 200 yuan ($29). Thus the amount of money one can grab largely depends on his or her luck, which is just the very fun of "gr...