People should understand this: A free tier is a loss-leader, intended to support sales of the paid product. If too many “…have been happily using Slack’s free plan for years”, then Slack will have to change the terms. Generally, storage and access to storage cost money. If you aren’t paying for it, it is definitely temporary, whether anyone says it explicitly or not. I don’t just mean in a “nothing lasts forever” way…
Here’s what companies don’t understand: if you promote your product through a loss leader — which is arguably how Slack became popular in the first place — changing your pricing at a later date will piss people off.
You’re trying to put the blame on the consumer here which never makes any sense from a business perspective. If your loss-leading pricing strategy was unsustainable from the start, that’s on you.
It doesn’t matter if the product is “worth it” because when you piss people off, they will gladly put in effort into migrating to another provider they can trust, because that’s what it’s all about: trust.
The latest Google Apps fiasco is a great example of this, where Google eventually had to backpedal due to the massive backlash.
It’s simply a consequence of just staring at the numbers, without properly understanding the psychological effect of taking something away from what is, despite the zero income but rather in a sense of trust, a customer. It’s just a customer you failed to get any revenue out of, and that’s your fault, not the customers.
Changing pricing pisses people off. Killing features pisses people off. Bad communication pisses people off. It’s really not that hard.
At the end of the day you’re making a deal with the devil with these overly optimistic loss-leaders, because you’re getting growth you never would have gotten otherwise. Failing to capitalize on that and then blaming the users while throwing features out the window is just not good business practice.