Speaking this morning at ILM:07 in Los Angeles, Russell Horowitz, chairman and CEO of Marchex, dismissed the idea that a clean slate is needed to communicate the value proposition of local online advertising to small businesses. He is betting on legacy sales channel like Yellow Pages publishers.

“Local sales forces sell lots of products,” Horowitz said. “They are successful because they deliver value and their reps invest time in learning how to sell them. Online is no different. Our most successful partners have invested in training their sales forces. … Our belief is the winners will have trusted local relationships. Bet on folks already there and already winning.”

Horowitz and Bill Day, Marchex’s chief media officer, presented the company’s business concept, which is essentially all about building a “mile wide and mile deep” local content network, and distributing it on a private-label basis through channel partners like Yellowpages.com and Comcast. Marchex describes itself as a local online ad company and a leading publishing of local content.

Underlying the rich local content network Marchex is building are roughly 200,000 unique Web sites with names like ChicagoDoctors.com, NewYorkDoctors.com and Indianapolisautorepair.com, each of which offers targeted vertical and local content.