This is a low-infrastructure, word-of-mouth hangout that runs on the trust that people who read the same local forum at least have that in common. It's not a networking event, it's not a sponsored thing, and the turnout is genuinely unpredictable — which is either the draw or the dealbreaker depending on your tolerance for showing up somewhere and seeing four people or forty. The host has been doing this long enough that regulars show up; "Mr. Nice Guy and his band of merry friends" is a real thing, apparently.

Practical tip: DM the OP or dig through the comment thread for the bar name before you head out. Don't just show up to every bar in a two-block radius hoping to find a Reddit meetup in progress — it won't go well.

If you've got two hours: show up, take the free drink, find out if you recognize anyone from the internet, leave on a high note.