[hdhzy]

> They can just wait to see what works, then copy it and kill the startup that did it first.

Well, if the only advantage is being first that's a big problem. The same goes for other startups: they can observe what works and deliver a better solution faster.

I see Slack innovating a little (custom menus etc.) but maybe it's just the market shifting - the chat alone is not interesting anymore as a standalone product but rather as part of a bigger solution.