From
Travel China Guide:
"
No. 8 in Chinese Culture
Because Eight (Ba in Chinese) has the similar pronunciation with 发 (Fa, meaning wealth or fortune), this number is very welcome among Chinese people. The popularity of 8 was obvious in relation to the Beijing Olympic Games which commenced at exactly eight o’clock eight minutes on the eighth day of the eighth month in 2008. When people choose telephone numbers, mobile numbers, house numbers, car identification numbers and important dates, 8 is usually the first choice."