But first, a little history. Kit Kat is a chocolate, crème-filled “4-finger” wafer bar created by Rountree Limited, a British confectionary company, in 1935. Originally named Rountree’s Chocolate Crisp, it was renamed Kit Kat in 1937, apparently after the “Kit-Kat Club,” an early 18th Century club in London associated with the Whig party.

Line extension was part of Kit Kat’s legacy. As early as one year after the candy’s creation, a two-finger version was introduced. But that pales in comparison to the variations that occurred after Nestlé acquired Rowntree in 1988. Nestlé took the UK’s best-selling candy and turned it into a worldwide juggernaut, creating endless varieties of Kit Kat in over 70 countries.

In the United States, ironically, Kit Kat is licensed to Hershey’s, a competitor of Nestlé. The Hershey Kit Kat line includes milk chocolate, white, extra crispy, king size, snack size, minis, and two seasonal versions: “Bunny Ears” during Easter and “Best Friend Hearts” during Valentine’s Day.

Elsewhere, Kit Kat is versioned by size: There’s the 4-finger, the 2-finger, the “Chunky” – essentially one fat finger, and “Senses,” a single finger topped with bumps of hazelnut filling. But things really got interesting when the brand started extending its line in different ways based on the country of origin. In France, for example, Kit Kat is also available in “Balls.” In Singapore, you’ll find “Bites.” In the Arabian region, there’s a 3-finger version.

Wait, we’re just getting started. In 2003, Nestlé wanted to see if it could add a little life to the Kit Kat line in the UK. According to the Post-Gazette, within a year, the company introduced a rapid-fire range of new flavors, including red berry, mango, passion fruit, strawberries and cream, tiramisu, and even “Christmas pudding.”

Apparently, the experiment was far from flavorful. Kit Kat sales plummeted over the next two years and most of the flavors were discontinued. Today, Kit Kat in the UK comes in the standard milk chocolate flavor, along with dark, orange, mint, and caramel. It has regained its position as the leading candy.

But the flavors that failed in the UK found new life in other countries. Nestlé has now turned Kit Kat into a truly customized-by-country brand, methodically versioning it to local tastes.

In fact, Japan is home to Kit Kat’s greatest adventure in line extension. Currently, Kit Kat is available in nineteen flavors in Japan, with availability varying by region. Some of the more unusual flavors include aloe vera yogurt, azuki red bean, cola and lemon soda, green tea, maple syrup, roasted corn, soy sauce (the nation’s most popular), and yubari melon. For a mind-boggling experience, check out all the Japanese varieties.

In Japan, Kit Kat is more than a confection, it is a favored collectible. According to Advertising Age, “Each flavor is only sold in the region for which it was created, a distribution strategy that has turned limited edition Kit Kat packages into coveted souvenirs for domestic travelers.” Because giving gifts is a part of the Japanese culture, collectible Kit Kats also make popular presents.

Nestlé pulled off another marketing miracle with Kit Kat in Japan by introducing an “edible” Kit Kat postcard which, not surprisingly, won an international advertising award. According to Nestlé, the name Kit Kat sounds like the Japanese words “kitto katsu,” which translates to “surely win,” so the company decided to connect Kit Kat to a campaign wishing students good luck during national exams.

Nestlé worked with Japan’s postal service to create a mailable Kit Kat bar with a space for a message that was made available in 20,000 Japan Post outlets. It marked the first time a private company partnered with Japan Post, and now “Kit Kat Mail” is a permanent product offered by the postal service.

While the Japanese may have the most unique line of Kit Kat products, the confection remains popular around the world. Nestlé says that over 400 Kit Kat fingers are consumed every second, and that every five minutes, enough Kit Kat is manufactured to out-stack the Eiffel Tower.

Kit Kat may come in endless varieties and be different in every country in which it’s sold, but to Nestlé, this is one sweet brand.

Barry Silverstein has been a frequent brandchannel contributor since 2007. He has thirty years of advertising and marketing experience and is currently a freelance writer and marketing consultant. He founded and ran his own direct marketing agency and held executive positions with Epsilon, a leading database marketing firm and Arnold, a major ad agency. Silverstein is the author of three marketing books, including the McGraw-Hill book, The Breakaway Brand, which he co-authored with Arnold CEO Fran Kelly.