Read the Cisco article here first, titled "Could You Ditch Email for Spark Overnight?" Then come back and continue reading below.
For "all internal communication" a room based chat app (whatever you want to call it these days) can work. However, only if you're in complete control of your entire team and their communication devices will it work fully. One key person whose device, network or ideology fits outside of the scope and it's a bust.
From the blog:
"If team members wanted to stay informed of what was happening in Switzerland, they needed to be part of the Swiss Spark room. All key information—weekly news, win messages, organizational announcements and changes, and all other official communication"
This is an interesting comment. Were all these pieces of information previously done through email? Are they creating more unimportant things for everyone to read just "because they can"? Here lies my main issue with chat apps, you can get flooded with new things to read, some important, some not. You'll end up with people who feel the incessant need to over share so everyone else is forced to weed through the junk to find the relevant information.
Adoption, usage and productivity rely on a few key factors - and this could be said about any new form of communication tool:
1. Understanding why there needs to be a switch - is communication being missed in the current method?
2. Top to bottom buy in and a desire to switch.
3. The time to switch with the understanding that with each new tool comes a learning curve.
4. Making sure people don't use emojis or post pictures of dinner and use the tool like a professional.
5. Being able to wrangle in the people who abuse the new method of communication - remember when you first had email and all the chain letters and other sorts of bullshit you received (uh, and still get)?
Of course their line of reasoning is solid to eat their own brand of dog food and switch/ditch, write a blog about it and use it for marketing. I can't argue with that.