WhatsApp for work: Slack is turning into a full-on messaging app

Forget email. The final frontier for Slack, as it tries to reimagine the way millions of people communicate at work, is the text message.

Email is a useful tool, but a blunt one. It mixes business communication with receipts and confirmation numbers; makes it easy to talk to anyone, but also maybe makes it too easy to talk to anyone. But text messages? Not every professional relationship graduates to text-message levels of intimacy, but the ones that do are the ones that matter most. And you might have an assistant read and filter your email, but pretty much everybody checks their own texts. It's the highest, most elusive rung of the business communication ladder, and it's exactly what Slack wants to replace.

Starting on Wednesday, any Slack user will be able to direct message any other Slack user. The new system is called Connect DMs, and works a bit like the messaging apps and buddy lists of old: Users send an invite to anyone via their work email address, and if the recipient accepts (everything is opt-in), their new contact is added to their Slack sidebar. The conversations are tied to the users' organizations, but exist in a separate section of the Slack app itself.

Connect DMs turns Slack from an app for chatting with co-workers into an app for chatting with anyone. It puts Slack on par with both enterprise tools like Microsoft Teams and free consumer services like WhatsApp and Facebook Messenger. "When someone opens up their phone," said Ilan Frank, Slack's VP of product, "if they're connecting with their friends, they click on Facebook or WhatsApp. If they're connecting with someone they work with, regardless of where that person works, they should be clicking on Slack."

That's a tricky thing to get right, both from a UI perspective and an IT one. But Slack is committed. This has been the plan since before Salesforce bought the company, and it feels even more urgent now. Slack needs this to work, in some ways, as Microsoft Teams and Zoom threaten to leave it behind. By expanding its purview, Slack gives users more reasons to try Slack, gives companies more reasons to adopt it and makes Slack an even more central part of the modern workday.

Slack Chief Product Officer Tamar Yehoshua was the guest on this week's Source Code podcast, talking about Slack's news and the future of work. Subscribe to the show: Apple Podcasts | Spotify | Google Podcasts

Still all business

One important thing for Slack has been to make sure that Slack is still mainly a tool for work. Sure, lots of people use it for other things — Slack's execs talk a lot about soccer teams that organize through Slack, which is either a very popular use case or just a particularly memorable one — but the team at Slack is building it to be used in the workplace. The difference starts with who's in charge. Often in businesses, Slack Chief Product Officer Tamar Yehoshua said, "all these out-of-band communications like WhatsApp and text, your administrator in a large company doesn't see and doesn't have access to them." She said Connect DMs have resonated with CIOs who like the idea of being able to control more information flow.

Slack has been fine-tuning these controls since it launched Slack Connect for the first time last year. Connect's first job was to let businesses share channels. The idea was straightforward enough: If your company is working on a product integration with another company, rather than talk to your respective teams in Slack and then cross-communicate in emails, just set up a Slack channel between both companies and have everyone talk there. Now 74,000 organizations use Connect, and Yehoshua said the growth trajectory is only increasing.

But what if your company and your partner have different privacy rules or data-retention policies? Slack has figured out an answer for that, too. "What we built is an author-aware system for collaboration," Frank said. Each company controls its own messages, which means in essence that a shared channel is actually two separately-owned spaces smashed together in Slack's UI. Either side's admins can nuke all their messages without touching the other side's. Slack is also verifying most Connect-using organizations, to help ensure that the tim@apple.com you're Slacking with is the real deal.

This kind of centralized control could be a win for IT departments everywhere. "You own what you have, and you disconnect, and they don't have access to it anymore," Yehoshua said. "This is huge. You could never do this in email." Both she and Frank were careful to say that Slack's rules still tilt toward individual privacy — it requires special, super-admin privileges to read private messages, for instance — but at the same time they understand that their primary responsibility is to the companies themselves.

Connect DMs mean that, in theory, Slack can be the only place most employees talk about work. If that happens, it creates a powerful growth engine for the platform, because using Slack no longer requires any kind of organizational buy-in. A freelance designer might use Slack to talk to all their clients, or a salesperson at a Slack-free company might use it to talk to Slack-using partners. Slack's best move has always been to worm its way into a company a few people at a time, before the bosses catch on and pay up. Now all it takes is one.

Or maybe all it takes is everybody. "Our vision for the future is, let's say you're working on the vaccine rollout," Yehoshua said. "You have pharmaceutical companies and hospitals and universities all working together. You can build a network of companies on Slack that are working together, sharing workspaces, sharing sets of channels."

The universal workspace

Ultimately, Slack will actually have a lot in common with a social network. Slack is working on user profiles, using tech it bought when it acquired Rimeto in 2020, that will give all Slack users a LinkedIn-style Rolodex of all other Slack users no matter where they work. (Same caveat as always, though: IT can opt out. Companies can turn off some or all of these features.) Rather than have each Slack instance operate like a corporate office users can invite guests into, Yehoshua wants Slack to be more like the workforce as a whole: not thousands of networks awkwardly connected, but a single social graph.

Yehoshua and Frank said that many people want to use Slack Connect just because it shrinks the number of inboxes and communication methods they have to worry about. But there's a version of that system — filled with unwanted invitations, constant @-mentions and unneeded information — that could start to feel like all the bad parts of email. Slack wanted to fix and replace email, not become it. The team hopes that by giving organizations more control over who can send messages, making it easy to disconnect from a conversation or never accept an invite in the first place, Slack can be as universal as email without being as chaotic.

The real killer app, though, might be apps. Slack Connect apps create a sort of shared app store between organizations, making it easier to start Zoom calls or share stuff through Google Drive. "The external communication component is what makes the Slack integration so interesting to us," Calendly Chief Product Officer Annie Pearl said. "We really specialize in the challenges that happen when you're trying to schedule externally — sales, marketing, all these functions where the majority of their job is to actually get meetings booked as soon as possible." Over time, Frank said, they're hoping to even help connect multiple systems, using Slack to pass data between different CRMs or in-house software.

There's a potential growth flywheel for developers here, too, by the way. "Obviously," Pearl said, "you can now access all of your Calendly functionality within the Slack application, which is great. And we also see this as a great way to acquire new users as well." One user sends another a Calendly link, which opens up an app in Slack for another user to schedule a meeting. The second user wonders what this Calendly thing is, and signs up for their own account.

Signing up all those new people will require convincing them that Slack is worth the effort, though. Email and text work just fine for a lot of people, and a huge number of people now spend most of their days in Slack-looking apps like Teams and Google Chat. Meanwhile, Slack overload is a real problem for businesses, with some employees feeling like they spend all their time in Slack and none of it doing their job.

To some extent, Slack's pitch is as simple as addition by subtraction, that having fewer places to talk to people is by default a good thing. But it has forced Slack to rethink how it onboards new users, since many won't have a team member to work with or a training forced upon them. "We're doing [a] much more progressive reveal for onboarding," Yehoshua said, "to give you access to functionality when you need it, but don't overwhelm you initially." Same goes for the way Slack teaches best practices for features like Do Not Disturb, @-mentions and channels, which can help stave off overload but aren't always obvious to new users. In both cases, Yehoshua said, there's plenty more work to do.

But Slack thinks the hardest work is already done. Slack Connect has been in the works for a while, and DMs essentially blow the doors off the feature. The timing of the announcement is not an accident, Frank said: The product team has spent months refining security processes, making sure the onboarding and interface make sense, and bringing a few customers into a new way of thinking about Slack. Now Slack wants to rewire everyone's brains. Slack isn't just a place to talk to co-workers anymore. It's not just an email killer. It's a place to do business, no matter what — or who — that requires.

Update 3/24: After Slack announced the new feature, a lot of users pointed out the possibility for abuse and harassment, particularly in the invite flow for Connect DMs. When we asked Slack to respond to the criticism, here's what Slack VP of Communications and Policy Jonathan Prince said: "After rolling out Slack Connect DMs this morning, we received valuable feedback from our users about how email invitations to use the feature could potentially be used to send abusive or harassing messages. We are taking immediate steps to prevent this kind of abuse, beginning with the removal today of the ability to customize a message when a user invites someone to Slack Connect DMs. Slack Connect's security features and robust administrative controls are a core part of its value both for individual users and their organizations. We made a mistake in this initial roll-out that is inconsistent with our goals for the product and the typical experience of Slack Connect usage. As always, we are grateful to everyone who spoke up, and we are committed to fixing this issue."