Slack is an insanely popular app, but its CEO thinks it's 'terrible'

Most Silicon Valley CEOs of fast-growing startups love to bend your ear over how their tech is changing the world because the tech is so clever.

But Stewart Butterfield, the CEO cofounder of Slack, can't stop telling the world that his app is terrible.

Slack is an app that lets coworkers chat with one another and has been taking the enterprise world by storm.

Launched just two years ago, it has already racked up 2.3 million daily active (20% joined in the last two months), and over 675,000 of them are paid users, which means $64 million in annual recurring revenue under contract, the company says.

You'd think those stats would be validating to the man responsible for it, Butterfield who, prior to Slack, was best known as a cofounder of Flickr.

Not so.

On Friday he tweeted "This is still as true now as it was 16 months ago" and referenced a story published by Business Insider back in November, 2014, with the headline: "Stewart Butterfield says his insanely popular app Slack is 'terrible' today"

As we reported back then, that comment came from an interview Butterfield did with MIT Technology Review when he was asked if he was working to improve Slack.

He answered with refreshing honesty:

Oh, God, yeah. I try to instill this into the rest of the team but certainly I feel that what we have right now is just a giant piece of shit. Like, it's just terrible and we should be humiliated that we offer this to the public. Not everyone finds that motivational, though.

In fact, on Friday, Butterfield underscored that he still feels that way, by tweeting out that quote again:

Disclosure: The Business Insider tech editorial team used Slack back in November, 2014, and we still do. In fact, Slack has spread across Business Insider and is now used by all the other teams, too.

The basic-ness of it is what we liked back then, and what we still like today, even though Slack now does all kinds of other fancy things, from custom commands to integration with other apps. Our team is particularly addicted to the "/giphy" command. (Try this one "/giphy Friday").

But apparently, there's no point in telling Butterfield that Slack is great. He's not satisfied yet.