I agree with both Ant & Alan that having a reference area to refer/link back to is the way forward. I have been doing this for some time if I see a question on Facebook that I know we have covered e.g. about Trig Points, YOSM etc which were covered in early editions of Seeker or if someone is asking about an events calendar. But we need more things to link back to.
I often use the 'schedule feature' on the Facebook page, so that posts appear at prime times or spread out rather than lumped together.
Twitter - Rich has represented the GAGB in the #UKGeocachingHour on Tuesday nights when he can and the group of users is growing. I tend to browse through tweets and retweet the odds ones, but apart from keeping our presence there, I don't how useful Twitter is. However if we had more resources available (with short url prepared) then it may be useful.
GAGB member since 2005
GAGB Committee member 2010 to 2016 (Chair 2012 to 2015)
UK Mega Event Chairman 2009 (Weston-super-Mare)