We thought there must be a reason why VoiceStar, Marchex’s Pay Per Call unit, had such a prominent presence at the North American Dealer Association (NADA) show in February. Now we know: The company has just formed a reseller partnership with The Cobalt Group, which provides services to 40 percent of U.S. auto dealers.

Internet marketing solutions are increasingly important , but “dealers are adamant about making their phones ring,” pitches VoiceStar President Ari Jacoby. Under the new deal, they’ll have “tens of thousands of custom, trackable phone numbers to use in offline and online campaigns. They’ll also have ads for the pay-per-call services places across several search engines and Web sites.

Cobalt’s emphasis on driving trackable phone calls gibes with a new Kelsey Group Survey of auto dealers and their use of new media. When it comes to calls to the dealer, the topline finding was that 51 percent come from classifieds; 48 percent from Internet Yellow Pages; and 33 percent come from email.