It's no secret I'm a big fan of Slack, the collaborative messaging tool. I've finally figured out why I like it so much, and why other apps like Hicphat and even Yammer are going to be the defacto messaging tools in business over the next 5-10 years.

It requires a personal example as an illustration.

Back when I first entered the corporate world (insert joke about a horse and buggy here), the idea of collaboration was always asynchronous. The concept was simple. I did page layout on my Mac, then I handed the document over to a copywriter who added the words. We didn't blink twice that this was our way of collaborating. It comes from the world of manufacturing, the assembly line that is always asynchronous. One part goes here, down the line, add the next part. It has formed the way we think.

The workplace has changed, however. Technology now makes it possible to do synchronous collaboration. This is not just instant messaging. While it's still such a new concept that most of us have a hard time accepting it, the apps are ahead of the game. Microsoft Word 2016, for example, lets multiple people work on the same document at the same time. This is big news, not because other apps don't already offer the feature (Google Docs, for one) but because it is the established tool in business.

Dropbox recently joined this revolution as well with its new Paper app. Once again, multiple people can work together, but in Paper, you can add photos or even lines of code as a group. (I'm guessing they will add even more productivity apps soon.) Forget the wisdom of the crowd; this is the power of multiple people working at the same time and becoming much more efficient. I can imagine this applying to photo-editing (multiple people using Photoshop to make changes), presentations (which is already possible in PowerPoint 2016), and almost any app.

I recently spoke to David Smith, the General Manager of World Wide SMB Sales at Microsoft, who reiterated these points. He said the modern workplace is changing and becoming more collaborative than we even realize. It's more than people sitting next to each other. It's more about people expecting to be able to work in a team on projects at the same time.

What Slack (and he says the Microsoft tool Yammer) has done is essentially meet the demands of this synchronous workplace. Email is too asynchronous. It's too slow. It's not team-oriented enough. The rise of social media is another example of how much we want to "work together" and at the same time. I'm always amazed at how quickly people respond to my questions and comments on Twitter-it's proof that we are working together, that we are not on an assembly line anymore.

"At the beginning of this line, you are one degree of separation from where it is headed," Smith told me. "But the change happening today-documents are morphing real-time, we have federated the ability to see the idea and thought process and recommendations and ideas and that ends up being a more efficient breakthrough at the end of the day. The classic assembly line no longer works. Folks want to see how their slice connects to the whole. If they get separated too much it hurts the output and creates more tension in the process."

Bingo, right? Synchronous collaboration is here. It might seem weird to communicate in real-time with an entire team in an app like Slack or Yammer, but it is more efficient and matches how the workplace has changed. Email, you have come to the end of your usefulness.