We found Mattermost to be more expensive than a paid version of Slack for our team of 16 after factoring in the costs of hosting, maintaining, and securing our

We found Mattermost to be more expensive than a paid version of Slack for our team of 16 after factoring in the costs of hosting, maintaining, and securing our own servers. It shifts the engineering cost burden onto your team. As others point out, Mattermost vs. Slack is more a discussion of self-hosted vs. 3rd party cloud-hosted.