Two Southern California firms have made Advertising Age's annual list of the largest search marketing agencies, released last week. Santa Monica-based The Search Agency, which is headed by David Hughes, was listed at number 12, and San Diego-based Covario, which is run by Russ Mann, was listed at number 25. Advertising Age reported that The Search Agency's 2009 revenues were $20.4M, and Covario's 2009 revenues were $8.8M. The Search Agency is backed by private equity firm JMI Equity; Covario is venture backed by Dubilier & Company, FTV Capital, and Voyager Capital.