A friend shared the thought that Slack is a little bit of a scary company to invest in because it was very easy to adopt.

"We had no trouble importing our historical message archive and just moving over to this new chat system very quickly. I worry about the long-term stability of this company because if something better comes along, it will be equally fast to switch and never go back," he said.

I wonder about this. Will people move to the new, better thing and ditch their existing product? Is that an existential threat to Slack?

I do know that the product IS pretty great and "team chat with searchable archives" has been tough to get right for a long time. (Internal IRC servers, IRCCloud, Campfire, Hipchat). But being technically excellent and fun to use is no guarantee of success (soft spot in my heart for Zephyr and platforms like Zulip).