The popularity of auspicious or lucky numbers is related to the idea of the pursuit of harmony in names by, for instance, using the radical or character for "metal" to compensate for apparent lack of "metal" in the person, or using the "water" radical to make up for a deficiency of same.
吉祥數字、幸運數字的風行，與八字中缺金補金、缺水補水以求中和的造命觀念有關。