If they want to grow beyond "just a team chat app" that takes a lot of engineering talent to do it quickly enough to compete with MS, Google, FB, etc. who are a

If they want to grow beyond "just a team chat app" that takes a lot of engineering talent to do it quickly enough to compete with MS, Google, FB, etc. who are all moving into this space full force. Additionally, to sell into the enterprise you need a sales team, so a lot of those are probably sales people on commission.