Slack has only 8 million daily active users but would very much like that to become 500 million

Slack cofounder Cal Henderson

Slack cofounder Cal


  • Slack has only 8 million users.
  • That’s a surprisingly small number given that the
    workplace chat app already feels ubiquitous.
  • Some sources value the company at up to $8 billion, due
    to Slack’s healthy revenue base.

LISBON — Slack is only at the beginning of its takeover of the
workspace, according to co-founder Cal Henderson. Although it may
feel like the office chatroom app is already ubiquitous
— and a solid majority of attendees at Web Summit in Lisbon
are already using it, according to a show of hands in the main
arena —in fact, Slack is not that widely used.

Henderson, the British programmer who started Slack with CEO
Stewart Butterfield in 2013, told Web Sumit there were about 600
million knowledge workers on the planet, who are all candidates
to use Slack as a communications tool. “We’d love to capture that
entire audience, but being realistic that’s not going to happen.
We’d be happy with 500 million,” he joked.

Slack has a long way to go. It turns out the app has only 8
million daily active users, the main internal metric used at
Slack. “It’s the only real measure we use to think about how
successful we are,” Henderson said. “We want to continue to drive
that up.”

Those users are valuable, however. About 3 million of them are
paying users, and Slack has more than
$200 million in recurring annual revenues

Slack has raised $1.2
billion in investment
and has been valued at $5.1 billion.
Others put its potential acquisition price at $7
$8 billion