First name (or given name) is the name that identifies a specific person. It differentiates a person from other members of a group, such as a family or clan, with whom that person shares a common last name (or family name). While last name is normally inherited, first name is “free to choose” and thus can be unique.
In some countries, however, only a few options seem to be highly popular. Many of my friends who were born and live in US, UK, or Canada have common first names. In English-based countries, Coke’s massively-distributed-but-highly-customized “first name” marketing campaign will work: each bottle of coke has its own first name label such as John, Sarah, Emma, and Alex. However, popular first names seem to be avoided in other countries. Most of my Korean friends have their own unique first names. In this country, Coke marketers may find it difficult to find popular first names and launch a marketing campaign using them.
Then, why do some people pick up popular first names and others avoid them?