Is it really success when people spend as much time as possible in a collaboration tool? …or is a post a success if a lot of people gives it a clap, like, heart or whatever emoji is available?

I would argue that there is nothing in above that is a valid measurement or KPI for a corporate collaboration tool. I think you should spend as little time as possible in a collaboration tool, but when you do you should have as short stretch to getting the answer / info / expertise as possible. If you capture that, it would be a great KPI.

A KPI would be when you get a swift and great answer to a question or gives information that helps making better decisions etc.

The real problem is that there are today no tool that can measure productivity gains, faster problem solving etc.

What about Microsofts Productivity Score then?

When I read about it and saw the launch video, I was very positive. Finally a company that makes productivity KPIs etc. It is a well delivered first step, with one huge flaw. It is perceived as a surveillance tool and not a way to help you become more productive. It gives managers a way to see how much you collaborate and use different tools etc. Not good. With that said, I think it can be a great productivity-dashboard if it is tweaked so it removes the “big-brother-sees-you”-feeling. An addition that would be valuable if companies could add their own KPIs. This given that most organisations value different data-point in different ways, Microsoft should not control that metrics on its own.

A note on Salesforce rumoured acquisition of Slack

In my humble opinion this, if true, is a financial trick. By purchasing Slack for $XB the share price of Salesforce will most probably rise and the purchase amount will disappear within the margins of the increased share-price. Operationally Salesforce already have the tools similar to Slack in Chatter (which is way better for collaboration btw). I do honestly not see the value for Salesforce customers in the addition of Slack to the product portfolio.

My opinion of Slack is well documented in the “Cutting the Slack“-post from 2016.