Ask HN: Organising a meetup: why do you go and what do you get out of them?

First of all, maybe this question has been asked before, in which case I apologise.

My company wants to organise a meetup for local programmers and/or dev enthousiasts. The goal is to have a fun evening for ourselves, do some networking with the outside attendees and learn a thing or two from other devs.

Seeing as I have never organised a meetup before I thought I'd ask HN.

How do you decide to which meetup you'd go and what are your goals when going to a meetup? Do you have any tips for us in getting our meetup noticed and gather attendees? Do you have tips with regards to talks/no talks, food and drinks, anything else I seem to have missed?