LinkedIn launches Mini Sudoku, pushing deeper into casual games that keep users coming back

LinkedIn on Tuesday released a new game for the professional social networking app's 1.2 billion users. It's a miniature version of Sudoku, an old game with a rich history.

The new Mini Sudoku is LinkedIn's sixth game. It's scaled down from the traditional 9-by-9 grid and meant to be completed in two or three minutes.

"We don't want to have a puzzle on LinkedIn that takes 20 minutes to solve, right?" said Lakshman Somasundaram, a senior director of product at the Microsoft subsidiary, in an interview with CNBC. "We're not games for games' sake."

The introduction has the potential to strike a nostalgic chord and spark competition with colleagues, friends and family members for how fast the puzzle can be solved.

As with other puzzles in the app, Mini Sudoku gets harder as the days progress through the week.

LinkedIn added games last year to increase the fun and give users something new to talk about with one another.

Millions of people play LinkedIn's games every day, a spokesperson said. The most popular time is 7 a.m. ET, and Gen Z is the top demographic. Of those who play today, 86% will return tomorrow, and 82% will be playing next week, the spokesperson said.

Launched in 2003 and acquired by Microsoft for $27 billion in 2016, LinkedIn remains in growth mode. Revenue increased about 9% to $4.6 billion in the latest quarter and membership reached 1.2 billion. Meta's social networks are more popular, with a combined 3.5 billion daily users and 22% revenue growth.

Unlike Meta, LinkedIn gives recruiters tools for finding candidates, and job seekers can apply for openings listed on the site. LinkedIn also now promotes a personalized feed of videos, similar to Google's YouTube, TikTok and Meta's own Facebook and Instagram.

LinkedIn's development of the game resulted from an encounter with Japanese publisher Nikoli, which popularized Sudoku.

Somasundaram and a band of LinkedIn associate product managers visited Nikoli's Tokyo headquarters late last year and spoke through a translator about puzzles with the publisher's employees. That led to weeks of meetings involving LinkedIn, Nikoli and Thomas Snyder, a three-time World Sudoku Championship winner who has helped LinkedIn with its gaming strategy.

The group hoped to make Sudoku more accessible, building several prototypes before landing on the board with six rows and six columns of squares.

"It's very easy to just make a Sudoku grid," Snyder said. "It's very hard to make art in the form of Sudoku. And that's what both Nikoli and we do."

Snyder is founder and CEO of Grandmaster Puzzles, a publisher of Sudoku books. With a Ph.D. in chemistry, he goes by the nickname Dr. Sudoku and has contributed to the hint feature in LinkedIn's Mini Sudoku and constructed some of the puzzles. With each day's puzzle, there will be a video showing how Snyder solves it.

"I think it's got the potential to be the largest of the games, just because it's going to have a lot of brand awareness from moment one," he said.

Howard Garns, an architect from Indiana, came up with a game called "Number Place" that required people to fill in a grid with numbers from one to nine. No number can be repeated in a row or column, and all nine numbers must appear just once in each of the nine 3-by-3 grids that make up the puzzle.

Number Place debuted in the magazine Dell Pencil Puzzles & Word Games in 1979. It only took off after Nikoli included a spin on the puzzle in the October 1984 issue of Puzzle Communication Nikoli under the name "Suji wa dokushin ni kagiru," which means "The numbers must be single," a Nikoli spokesperson told CNBC in an email.

Readers abbreviated the puzzle's name, calling it Sudoku.

At first, the publisher employed both the long name and the shorter Sudoku title in Puzzle Communication Nikoli. In 1992 Nikoli started using only the Sudoku name, the spokesperson said.

U.S. and European newspapers began publishing Sudoku puzzles in the mid-2000s. Sudoku joined The New York Times' NYT Games app, which boasts 10 million daily users, in 2023. More than 100 media companies have licensed Nikoli's Sudoku puzzles, the spokesperson said.

"The daily puzzles will only be available on LinkedIn each day, but we are looking forward to republishing selected puzzles from those in our magazine," the spokesperson wrote.

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