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Slack co-founder's goal: Grow users by more than 6,000%

Alanna Petroff
Senior Economics Correspondent at Yahoo Finance UK
Slack co-founder Cal Henderson has big growth plans for his company. Photo: Noam Galai/Getty Images

Slack co-founder Cal Henderson has big, brash goals for his office instant messaging business: Grow Slack’s user base from 8 million daily active users to 500 million.

In other words, increase his user base by more than 6,000%.

Henderson, the company’s chief technology officer, said his firm measures its success based on its daily active user numbers. He made his comments at the annual Web Summit technology event in Lisbon, Portugal, on Tuesday.

Slack is known for being a beloved tool for tech workers, but it’s also used in a range of other industries, including media, hospitality and even real estate. Henderson said about 60% of Slack users are in non-technical roles.

“We have customers from the smallest family businesses, shops and estate agents … through to the majority of the Fortune 100 and FTSE 100 [companies],” he said.

Henderson said it’s a constant challenge to try to convince people to get away from their emails and use Slack instead. The “inertia of doing things in an old way” is one of the company’s biggest challenges, he said.

“Email has been the primary mode of communication inside business for more than 30 years. Convincing people, or just really telling people that there’s a different way to work, I think, is the biggest challenge. There’s huge unlocked potential there though,” he said.


Slack has raised $1.2bn (£900,000) in funding since 2010, according to CrunchBase. It most recently raised $427m (£328m) in August, its largest ever fundraising round.

Slack, which is based in San Francisco, California, has more than 1,000 staff.

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