I didn’t know Hipchat was mostly bootstrapped. It’s great to hear their story from inception to selling to Atlassian. There are lots of insights into the “why” and “how” they did what they did.
Awesome interview! Thanks for sharing.
For me it’s a bit more interesting and personal because I happen to work for Atlassian (via a contractor) and we did create an alternative HipChat before 
It was over 6 years ago when we had the same problem like HipChat guys had and I actually created a software (we called it vodka) that would solve the same problem HipChat did.
First we used it internally in our small company, then some of the folks from Atlassian headquarters used it too. I left the company to do my own business but guys kept investing in this software. What they didn’t put mind to was that it was a global problem. So they didn’t think about selling it. The started thinking about it when it was too late - HipChat was already established and they didn’t (again) put mind into competing with it.
So they basically resigned and some short time after Atlassian decided to buy HipChat
I was sorry for them a bit. But the lessons learned is that if you have something valuable don’t be shy to get out to other people because they might need it too. Every small thing you do to help yourself can help someone other.
I understand why they struggled with actually marketing their solution - having a coder hat all the time they were constantly thinking about improving it, not selling it. And you need to sell your idea, market it and talk about it constantly.