File this one under why-mess-with-success: Coke is bringing back its "Share a Coke" program after a successful run last year in which people scooped up bottles in search of their own or a friend's name on the label. This summer, the brand will extend the program to include more names and to cover more package sizes and formats, according to a person close to the company familiar with the matter.

Last year, the marketer used the 250 most popular first names among teens and millennials and the program was limited to 20 oz bottles. Additionally, colloquial phrases were put on on cans, such as "superstar" and "bff." This year, the number of names used is expected to at least triple.

The program debuted in Australia in 2011 and was taken to other international markets.

While it took Coke a few years to bring "Share a Coke" to the U.S., it was an unquestioned hit, contributing to improved sales trends. For 2014, brand Coke grew sales volume for the first time since 2000, according to Beverage Digest.

Lucie Austin, who helped create the program while director of marketing for Coca-Cola South Pacific, stated in an interview last year posted on Coca-Cola's corporate blog that "our research showed that while teens and young adults loved that Coca-Cola was big and iconic, many felt we were not talking to them at eye level."

She added: "Australians are extremely egalitarian. There's a phrase called 'tall poppy syndrome.' If anyone gets too big for their boots, they get cut down like a tall poppy. By putting first names on the packs, we were speaking to our fans at eye level."

In this video, the South Pacific marketing team explains how they pulled it off: