Slack

Slack is a workplace messaging platform built around channels, threads, and third-party app integrations, originally designed for internal team communication rather than public community building. During the 2016 to 2017 wave of blockchain projects and ICOs, many teams repurposed Slack as their main public hub anyway, inviting investors and early adopters into open channels alongside internal developer discussion.

The fit was awkward from the start. Slack's free tier was built for small, closed workspaces: it limits visible message history (a rolling 90 day window today, after an older 10,000 message cap) and offers no native way to vet who joins through an open invite link. Projects with communities running into the thousands ran into broken invite links, older messages vanishing behind a paywall, and admins unable to moderate at scale. Slack also lacked built-in protections against impersonation, so scammers regularly posed as team admins to run phishing schemes and fake giveaways inside crypto workspaces, a pattern widely reported during the ICO boom.

By 2018, most crypto projects had migrated their public communities elsewhere. Telegram offered unlimited group sizes, broadcast-style announcement channels, and stronger anti-spam controls without requiring a paid plan, while Discord added role-based permissions, voice channels, and moderation bots better suited to large, self-organizing communities. Today Slack survives mainly as an internal coordination tool for core teams and DAOs rather than a public front door, while open crypto discussion happens almost entirely on Telegram, Discord, and X.