I'm a member of a very active bike club and we use a Facebook Group to keep people up to date. In the past, our rideout and event calendar was pretty much set in stone by the end of January and that was fine up to a point. Now though, given a good weather forecast and a bit of free time, it's much more fluid in the sense that Thusday or Friday evenings will almost always see a " I'm out Sunday, anyone want to join me, we're off to x, meet at somewhere at hh:mm". Works a treat.
I don't use Facebook much other than that cos most of peoples postings are so samey and vacuous, some good jokes though. Twitter I don't bother with now, although I did follow Hutchy's recovery for a while.
So I won't bother with the IOMTT facebook or twitter feeds.