Having no Facebook event for a milonga is no bad thing. The milonga in Pant had no Facebook event and is in the middle of nowhere yet thirty people appeared. Facebook is notoriously unreliable for showing true numbers yet if not enough people show they are going it can occasionally put off those not savvy to this, though losing those swayed by such unreliable things is probably no great loss.
Still, I wonder if the few organisers who do not use Facebook for their events do so because they expect numbers to be so low they think it might do more harm than good to advertise this way. This would not necessarily put me off. I don’t mind small milongas and have had a very nice time with a few good dancers or just nice people.
The other problem with Facebook events is that they are frequently not in synch with the organisers’ calendars. One doesn't know then whether an event is on or cancelled. I have seen this with Viva tango (empty calendar but an event on Facebook) and Northern Tango Academy (NTA) only last week. I have a feeling there may have been until recently a calendar on the website. In any case there was enough ambiguity around the events that I had to ask whether their Una noche de garufa milonga was on in November or not. But it is almost unfair to name names because it is so very common. I notice the NTA's Tango in Liverpool and Tango in Manchester groups on Facebook are closing to merge with the main NTA group, perhaps to minimise such maintenance.
The problem is less with milongas like the Manchester Popup (review) which because it doesn’t advertise classes, worskhops or shows only has a Facebook group and events, not a website. This approach is lower maintenance too.
For advertising I would rather organisers either just used their own site plus a national site like TangoTimetable or TangoCentral or a Facebook event; not, incidentally, a Facebook group cluttered up with adverts from other organisers. That is just a pain. All that cross-advertising can be avoided if organisers and dances used the same national site. I mean what's not to like? And besides - those not local can easily find what’s on for a weekend away and can check accuracy in one place: the organiser’s own website or Facebook event (but please not all three).
I say please advertise using a national site, like the Dutch do, with tangokalendar.nl and torito.nl. Honestly it's easier to know what milongas are on in the Netherlands than it is in the UK. While I can hold quite a lot of tango group names in my head I can't hold them all and for weekends away I really want to know what is on in certain regions without trawling Facebook or bothering all my acquaintance. Please suggest it to your local organisers. You will surely get more visitors in general that way (assuming you want them!). Or the Dutch will.
I'm so sorry. I gave in to bold for non-linked text. I'll try not to do it again.
The only reason I may put down “interested/going” to events on Facebook is to remind myself what’s on and usually I do that more for non-tango events when there may end up being several things to choose from at a weekend. Otherwise, the only purpose would be to tell others one is going to a milonga and I don’t expect whether I go or not to sway anybody.
When a friend, travelling, got in touch privately to ask if I was coming out to dance the compliment was lasting and the effect disproportionate to that small act. So if there is someone I would really like to dance with I hope I have learnt from that and will do the same.