Slack has some customers that are willing to pay, there are millions of people who use Slack for free, Slack needs to find a cost effective way to cover those e

Slack has some customers that are willing to pay, there are millions of people who use Slack for free, Slack needs to find a cost effective way to cover those expenses. Slack service is not remotely unique, their competitors both large and small are profitable ie Basecamp/Microsoft/Google