How the hell does one stay active on all these and get time to do anything else?
Do you just repost the same content everywhere? Is there any real benefit from joining and investing time into these communities?
I treat each platform differently. Reposting the same content across platforms is too easy and comes across as unprofessional. You need to leverage the unique selling point of each channel you're on. So Twitter would be handy for iterative small changes announcements, Facebook could be for more long-form content and using groups and pages to elaborate on topics. Reddit could be used for AMAs and forum-like discussion, aswell as Q&A.
The best brands find a network that works for them and double down.