[mike_d]

Free. The vast majority of Slack instances are groups of friends, common interests, and small businesses. This might be a super compelling feature for a model rocketry club, but they can't even afford to upgrade to paid Slack instances.

Now launch an enterprise plan. It should be hundreds or thousands of dollars a month, whatever keeps you afloat. Include SLA guarantees and support. Enterprise users are going to have you engage lawyers to redline contracts and do security audits since you are plugging into their internal communications. Saying you have "commercial grade encryption" doesn't mean anything to the people who will pay your bills and you are going to have to pay for outside pentests and privacy audits.

But most importantly start working on your next Slack app and diversify your income. In all honesty this is a feature built on a bug (poor text rendering in Slack). If a billion dollar company needs that bug fixed they are just going to pressure Slack during the next renewal to avoid having to pay you.

[Mandatum]

I think this is pretty on-point.

The majority of your income will be from tech companies and education/research firms that have bought into Slack (which is far and few, most are all-in on Teams with just student groups in Slack).

Put out what you can for free, then slap on the commercial licenses or options for your potential customer base. User or workspace per month with a very slight discounted annual and heavily discounted multi-year option. It's mostly about adoption at this point, outbound marketing won't work unless you're actively demoing the feature to your customers.

And a lot has to align for that; Slack admins allowing it, a business unit willing to sponsor the budget, security & compliance.

Best of luck!