As a B2B SaaS app founder I dream of the day when our app generates this type of positive, organic coverage so effortlessly. It's no wonder Slack are growing at such a rate, they've built something that provides a serious amount of value to people.
1. Whenever you catch yourself thinking that something uncommon is effortless, you're probably not seeing what's going on behind the scenes. Or at least– getting to the point when you've set the flywheel in motion (and people are trying to use your product or idea as a centerpiece for discussing something of their own) is non-trivial! But I'm sure you know this.
2. There are B2B SaaS apps that provide a serious amount of value that grow nicely, but still don't grow as quickly as Slack does– Slack is kind of an outlier in this regard.