I'd imagine a Twitter presence helps forums such as ours gain new members. It knows I like family history and archives, so keeps showing me 'stuff' it thinks I should follow. So my Twitter is full of genealogy stuff, museums, libraries, archive collections, bookbinding demonstrations - as well as cats, art, music, gardening, police horses and military aircraft. Don't ask.
Facebook does have a lot of good genealogy help groups... counties, countries, provinces, dna etc. I have joined several..the Lincolnshire is one that has helped me. Most are great, but the moderator of one that shall remain nameless is very nasty to a lot of members who ask for help, but are told they need more information to get that help.
I recently joined a local genealogy group on Facebook and have tried to help several people. One woman asked about a couple and gave names of their children, saying they had been born in the early 1900s. I found the family, who were much older than she thought, but definitely the correct people due to an unusual combination of names and the area they lived in. The woman thought that the man had changed his name, but he hadn't - I found evidence that there were two separate families. Afterwards I noticed that she'd made a previous enquiry about the same relative, with a different surname and a different place of birth. I queried that but she hasn't bothered to get back to me, so she can sort them out for herself! I've also found that people will post that they're looking for a particular family in a certain area, but when I ask for details like dates and places of birth so that I can help with the search, I get: "Oh, I know all that - I just want to see if I can link up with any other relatives in the area." Think I'll give up on Facebook groups - proper genealogy forums are much better.
I am a moderator on a local area forum which does try and answer genealogy questions, though it is mainly a history forum. Recently we have thought it useful to add a post saying that a "please " and "thank you " is courteous and shows appreciation for those who gladly share their knowledge. Some posters are so abrupt as to be truely rude (such as "any XXXXXs in the YYYY st area") and many do not seem to think (as has previously been stated) that it is necessary, useful or courteous to give information they may have as an aid in the search
I have been very fortunate in the 'groups' I join on f.b. in that all are very polite & helpful, if they need more information they will suggest that, & when anyone is rude they get the boot. Sadly it's in the nature of some people that their approach is quite vinigar-y & their attitude to beginners meant to imply their greater worth gives the opposite impression. Always some like that in the bunch of whatever group gets together.
This mention of "other sites" has reminded me that I haven't visited one on the three sites I'm a member of, I have a limited Family Tree on the site but over the last couple of years of replaced one or two ancestors. First I need to try and remember who they are!
Although I have joined a history group on Facebook, I think I will just keep my family history to this wonderful forum