According to Deloitte’s 2015 Millennial Survey, six in 10 millennials say that a “sense of purpose” is what drove them to work with their current employers. They want to work on something that matters, something that has a clear “why.”

Simon Sinek articulated this driving motivator in his TED talk, “Start With Why." In it, he says again and again: “People don’t buy what you do. They buy why you do it.”

And yet thousands of companies still create a gap between what they sell and their driving mission. It means they’re leaving opportunity on the table — to retain their millennial workforce, to build something of lasting impact, to drive lifelong customer loyalty.

If there's one shining example of how mission-driven companies are building purpose into what they do, it’s Slack. 

Slack is an internal work communication and collaboration tool — which is in no way new or even very exciting. So what is Slack’s “secret sauce”? Why has today’s workforce embraced it so readily?

What sets Slack apart is its unwavering dedication to mission: Slack embraces its mission statement, reinforces it at every turn and appears to have every intention of changing the world. 

That’s the kind of mission-driven company culture that millennials want to be a part of and pay money for. Slack helps its users create the future, helps them build better teams and better work lives. 

Slack is also, not coincidentally, one of the most successful startup stories of the last decade. And, as of April 2015, it is valued at $2.8 billion and is growing like wildfire in companies large and small.

Let’s take a look at how Slack is creating a core mission that resonates internally, spreads externally, and has ignited a movement for its customers.

1. The CEO Repeatedly Articulates the Company Mission

Back in February 2014, CEO Stewart Butterfield released an epic blog post based on an internal company memo he sent out in 2013. The post detailed Slack’s mission and sold the internal team about the work that they were doing, day in and day out. 

It’s a rousing, going-to-battle call to his team. There are many “mic drop” moments in this post, but here is where Stewart gets at Slack’s “Why” and drives it home:

why people deserve slack

In every interview with Stewart, he articulates this mission and purpose with characteristic candor and no-holds-barred attitude. For instance, in a BuzzFeed interview about Slack’s latest $80 million investment to integrate with all kinds of workplace software (expense reporting, CRM tools, etc.), Stewart said, “The bid to change the future of work is the goal.”

Slack's employees never back down from this ultimate aim, and their work proves this again and again.

2. It Backs Up Its Mission With Internal Culture

Not only does the CEO reiterate the mission over and over with the external world, but the internal community rallies around Slack’s mission in all of their actions. And it’s easy to imagine why, given Stewart’s crystal clear articulation of that mission.

It’s also because Slack’s internal culture is about inclusion and transparency, two values that are hard to come by in corporate work environments. Slack, for instance, isn’t about touting “diversity” in a clinical sense. Slack talks about its focus on diversity in terms of the emotional cost of not being inclusive, about the long-term benefits of multiple perspectives on a company’s ability to build the future.

On Martin Luther King Jr. Day in 2016, Slack employee Erica Baker shared an internal memo from Butterfield on Medium, in which he shared how he hoped his team would honor that day.

In addition, back in September, Slack released its own diversity numbers, with the caveat that they knew they could do more and promised to do so in the future.

slack diversity numbers

3. Launching Side Projects That Further the Mission

As the Slack mission statement says, Slack is much larger than its communication platform. That’s what makes mission-driven companies so interesting. They are much larger than the products they sell. They are selling a way of being, an openness to ideas — values that people can rally behind.

To this end, the Slack team often releases projects that further their mission even while they may not have anything to do with the end-product itself. These days, employees have built things like a Slack Shop where all proceeds go to charity, a job board for Slack-friendly companies, and have just launched a platform upon which other companies can build Slack integrations.

These are the kinds of projects that will allow Slack to innovate in the future, with the added benefit of a captive and loyal audience ready to buy into new products and features that align with the overarching Slack mission.

Slack’s mission radiates from the inside out: from internal employees who rally behind the company at every turn, to loyal Slack customers who serve as ambassadors for the company wherever they may work and in whatever community they may create.

They open Slack up to the outside world, allowing others drawn to their mission to join in. This is how companies must operate in order to make it in the world of rapidly changing consumer expectations.

How does your company start to become mission-driven? The mission of any company must start at its core, internally. Most companies sell products but stand for nothing, while others are prepared to take on the world and keep customers for life. It’s no mistake that Slack has created avid fans and loyal customers. They didn’t do it by saying empty words. They did it — and continue to do it — by standing for something and backing that stance up with the company’s actions at each and every turn.