@anildash
I'm not in your field but hold office hours for information exchange or follow-ups from previous discussions. I like to think they're successful from a community standpoint.
Small advice: always have an agenda to give it structure (welcome, a short topic, q&a, other business, fun Prince fact, peace out). And have support/moderation in the space to help keep the vibe good and manage the audience.
FWIW I'd visit your office hours.