Slack is letting paid users message any other Slack user (yes that includes friends at other companies)
A product with an NPS ("consumer favorability rating") similar to that of Netflix/Amazon/Airbnb, backed by the tech giant that is Salesforce, was always going to see tremendous growth in my opinion.
What's interesting now is the 'bet' to be the unified virtual workplace of the world. Is there a future where:
- You and your friends across industries use Slack during work hours to chat?
- You read / inform / update yourself with news through "public" slack feeds?
- You manage / contact (a large portion) of your professional relationships through Slack?
The details are what will matter most - how they handle privacy concerns and declining productivity will be interesting to watch