Our group has a website, Facebook page and a Facebook group that is about our retreats. You said you want to build membership and I don't think social media has grown our membership. Social media helps to keep us all informed. Example we have a workshop today and I could not remember when it started. I went to our social media to find out the time. Our guild has grown over the last 10 years from 40 members to 110 members and we have maintained the 110 over the the last 7 or 8 years. I think we grew because of workshops, inviting people to join us and really working hard on making everyone feel important and welcome. We also have a wide variety of quilters who are so open to help each other. Good luck in growing your guild.