The media sure is fascinated by Arianna Huffington and her eponymous Web publication. The latest installment, a Michael Calderone story in Politico, focuses mostly on what The Huffington Post means for age-old debates about blending coverage of sex and politics and the role of objectivity in journalism. But Eric Alterman’s description of the site, quoted by Calderone, stands out. HuffPost, Alterman said, functions as a “‘community newspaper’ for the liberal community.”

That brings to mind a point Michael Shapiro makes in his piece on the potential of free/paid hybrid news sites in the current issue of CJR. (Shapiro’s piece will go live on the site next Tuesday.) “General news has long been predicated on the idea that people’s primary interest in news was defined by where they lived,” Shapiro writes. But major papers like The Wall Street Journal and, increasingly, The Washington Post now define their primary area of coverage not as a physical entity but as an idea. And, he argues, regional papers in places like Detroit or San Jose might gain new, and paying, audiences by doing the same thing–by becoming the authoritative source of news about, say, the auto industry or Silicon Valley.

The analogy only goes so far–Huffington Post doesn’t charge its readers, of course; by design, the audience it appeals to is so large, and its staff so comparatively small, that it doesn’t need to. But as Alterman notes, the site understands the value in identifying a discrete community of interest and doing what you can to serve it. At the moment, that’s a task a lot of news organizations are facing.

Greg Marx is a CJR staff writer. Follow him on Twitter @gregamarx.