It’s definitely difficult to get a group entrenched in one platform to switch to another – especially without a full migration option. One challenge that might arise on a different platform is realizing just how a community was due to the platform’s network effect vs. the actual value the community provided. Discourse naturally doesn’t have a network effect like that as we don’t have a broad-based network of any kind – just lots of variously sized communities dotting the Internet landscape. And what makes a Discourse community stick is the inherent value its members find in discussing topics together, not just the platform itself.
As far as mobile goes - I’m curious if you see an advantage Facebook has over other platforms (including ours) on mobile?