Chevrolet found viral gold with #Chevyguy and #technologyandstuff. Rikk Wilde, the Chevrolet dealers&#8217; representative, got tongue tied giving the World Series MVP Award to the Giants pitcher Madison Bumgarner and fumbled his way through his discussion of the new Chevy Colorado. But instead of being a disaster, the Internet lit up and people embraced it for its authenticity. This led one business publication to declare that &#8220;The Auto Industry Has Mastered Viral Marketing.&#8221;A viral win like this is certainly welcome news for Chevy. But it&#8217;s only one small bright light in what has otherwise been a deteriorating word of mouth (WOM) environment for Chevrolet and the rest of the domestic auto industry for the past few years running.Sharp Declines in WOM for Ford, Chevy and DodgeNew research reveals that word of mouth for the domestic auto industry has been in steady decline for the past three years, with the combined share of conversation for Detroit&#8217;s big three dropping sharply while word of mouth for the foreign (non-luxury) automakers is gaining.Source: Keller Fay&#8217;s TalkTrack&#174;, 2014More specifically, Chevrolet&#8217;s weekly word of mouth impressions have declined 9% over the past two years -- that&#8217;s a drop of more than 7 million word of mouth brand impressions per week. Ford&#8217;s decline has been even more substantial -- a 13% decline, or 15.6 million fewer word of mouth impressions each week. Dodge too, saw a pronounced decline, with -14%, or 5.6 million fewer weekly WOM impressions.Subaru is Auto&#8217;s Biggest WOM GainerWhere have the auto talkers gone? The biggest gainer during the 2012-2014 timeframe has been Subaru, which has seen an 81% gain, or 5.2 million more word of mouth impressions per week. Other imports have gained as well, including Audi (+36%), Hyundai (+16%), Nissan (+7%) and Honda (+6%).Source: Keller Fay&#8217;s TalkTrack&#174;, 2014The silver lining for the domestic manufacturers is that collectively they still have the greatest volume of WOM. However, in 2011 and 2012 they held a 20 percentage point lead over the imports. Currently, their declining word of mouth means their lead over the foreign nameplates has shrunk to only 8 points.Blue Collar Workers and Homemakers are Driving the WOM Decline for The Big ThreeThe two groups with the strongest word of mouth for the domestic auto makers are the ones whose word of mouth has dropped the most. Blue collar workers and homemakers have registered declines of nearly 10% during the past two years in terms of conversations about domestic cars. In both cases, their conversations have shifted to foreign manufacturers.Why does this matter? Because research shows that word of mouth is heavily tied to purchase intent, and particularly in high consideration categories we&#8217;ve seen that a substantial amount of sales can be attributed directly to word of mouth advocacy. An unscripted moment during the World Series can lead to a viral sensation as noted above. But the longer term and harder challenge for Chevy and the rest of the domestic auto industry is to get Americans talking again on a day-in and day-out basis, and the research shows that to turn that around they are likely to need a lot more than one moment of glory for the Chevy Guy touting &#8220;technology and stuff.&#8221;Ed Keller, CEO of the Keller Fay Group, has been called "one of the most recognized names in word of mouth." His new book, The Face-to-Face Book: Why Real Relationships Rule in a Digital Marketplace, was recently published by Free Press/Simon &amp; Schuster. You can follow Ed Keller on Twitter, Facebook and Google+, or contact him directly at firstname.lastname@example.org.Read all Ed&#8217;s MediaBizBloggers commentaries at WOM Matters.Check us out on Facebook at MediaBizBloggers.comFollow our Twitter updates at @MediaBizBloggerThe opinions and points of view expressed in this commentary are exclusively the views of the author and do not necessarily represent the views of MediaBizBloggers.com management or associated bloggers. MediaBizBloggers is an open thought leadership platform and readers may share their comments and opinions in response to all commentaries.