Plenty of startups have tried and failed to make enterprise software sexy, but Slack made it viral. Its growth rate is unheard of. Both Slack’s daily user count and its paid seat count are up 3.5X in just a year. Tons of people have still never heard of it, but with this momentum, they probably will soon (it’s workplace chat).
What the growth means for Slack is network effect. Each person who joins makes the product stronger for everyone. Each one who hears about it or uses it to organize outside of work becomes more likely to infect their whole company with the Slack virus. And while competitors might be able to clone its basic chat features, they can’t clone its community.