A recent piece on Yelp written for San Francisco magazine by one Karen Solomon roughs up the local-reviews website, but Solomon's critiques are mostly on target: The site's audience is insular and dominated by Bay Area residents; it has struggled to expand to other cities and define a business model. Just one small problem: San Francisco magazine reviews local businesses. In between throwing lavish parties, Yelp runs a website which lets its users do the same. So the two compete, at least in theory.