13.2. The Topics: What Are They Talking About?

Communities emerge to discuss something, whether within a Facebook group, a mailing list, an IRC channel, a blog’s comment thread, or a Twitter hashtag. You want to be aware of any topics that concern you.

You find these topics by searching for them in the aggregate (most popular Twitter hash tags or most active Facebook groups, for example) and in the individual (who’s discussing a topic on Twitter or which Facebook users are members of a group). By tracking topics in the aggregate, you understand trends, community size, and growth. By tracking individual threads, you find evangelists and brand promoters who can help encourage the spread of your message and make others aware of the community to expand membership.