Slack and the law of conservation of clutter

Is Slack an Email Killer?
Over the past few years, we’ve seen several companies release their latest Email KIller. As in, “Use our great product and you’ll never need internal email again!” Notably, a few of these are Asana, Jive, Chatter, HipChat and of course, the new darling, Slack.

While many teams using Slack report that it reduces the amount of internal emails in their inbox, it definitely doesn’t kill email and make it go away. Some argue “not yet!” That might be the case, nobody really knows. In my humble opinion, email is not going away anytime soon.

Being an experienced Slack user myself — and talking with other users who use it in the workplace — has led me to believe that it’s probably true: Slack does reduce the amount of incoming email. However, I would argue that while users may get less mail, this product does little to reduce the amount of clutter and noise. It merely shifts it from email into Slack. Some might even want to suggest that it actually invalidates the law of conserving clutter by increasing the noise.

I don’t have hard data to back up any claim that Slack increases or reduces clutter. Yet, based on my experience and analysis of the product, I believe that Slack is at best merely conserving clutter. And most likely it’s actually generating more of it.

Let’s do the math!
First let’s define “Clutter” as the sum of the number of words communicated to or from all users in a certain communication chain over email or Slack. For example, if a user receives an email with the words “Hello World” in the body the Clutter number would be 4 = 2 (words) x 2 (users: sender / receiver). Likewise, if a user sends the same message in a Slack channel with three members the Clutter number will add up to 6 = 2 (words) x 3 (channel members).

Slack’s communication model is based on channels and one on one communication. A typical user belongs to several channels corresponding to the various projects and working teams he belongs to.

Let’s look at an example. Bob is a member of a Slack channel called “Project X”, with 6 members. Bob sends a message, “Hello World” in the “Project X” channel. All channel members see the message. Melissa replies with “reply to hello world”. In this scenario, the clutter number would add up to 36. Bob’s message contributed to the clutter count 12 = 2 (words) x 6 (members) and Melissa’s message added an additional 24 = 4 (words) x 6 (members). The same use case with email would yield the same clutter number 36. Bob would include all the channel members and send the message followed by Melissa’s reply to all.

Now, let’s look at a similar use case where Bob wants to send the same message related to “Project X” but this time it is relevant to only three channel members. Using Slack, Bob is most likely to follow the exact same steps above and simply post it in the Slack channel hence ending up with a clutter number of 36 (assuming Melissa replies). If Bob were to use email, he would handpick only the 3 members that the message was originally intended for, with Melissa’s reply the clutter number is equal to 24 (8+16). Bob’s original message contributed 8 and Melissa’s reply 16.

Slack vs. Email
The fact that Slack forces users to send messages to all team members creates more clutter. Email, by forcing the user to handpick recipients, reduces the amount of clutter.

There is always side conversation in any team dynamic. With email, the non-interested parties are completely oblivious to many of those conversations. In Slack everybody is exposed to everything within the team.

It’s not uncommon to include non-interested parties on an email thread. But at least with email, the original sender needs to make a conscious decision who to send it to and that in itself filters clutter.

It is also true that in theory one can create a channel for every side conversation. Anybody who uses Slack knows the friction associated with doing so is very high. Slack was not designed to be used that way. Finally, there is also the @mention feature in Slack. While it does serve to draw the user’s attention (by notifying a user someone’s explicitly addressed him), other users are still exposed to everything that is happening in the channel.

Slack is a good product that will continue to see adoption and help teams better work with one another. By no means am I advocating that we go back to email only. However, Slack is not the solution for clutter nor is it a method of noise reduction. It’s simply a better collaboration platform than email.