Facebook – a social networking site located at facebook.com.
forum – an online community where visitors may read and post topics of common interest.
like-gate – a barrier requiring a user to “Like” a brand’s page before they can access certain content from that brand on Facebook.
moderator – at a forum, someone entrusted by the administrator to help discussions stay productive and within the guidelines.
netiquette – short for network etiquette, the code of conduct regarding acceptable online behavior.
social networking – the process of creating, building, and nurturing virtual communities and relationships between people online.
word-of-mouth marketing – a marketing method that relies on casual social interactions to promote a product.
see also:
Tools > Social Media Services & Tools 
Salary > Director of Social Media