I think it's a good idea to have a facebook page. I bet I've talked to dozens of interested music lovers, since I started building two months ago, who didn't know you can buy kits and "build" your own speakers. Especially good ones. Wouldn't facebook be seen as totally free marketing? Also, can't you share links to pictures and pages on facebook? I am a total casual user of facebook, but I think that's the case.
I am sure AC will always be the prefered method of learning and sharing audio ideas.
Ben