Fall is here, and with it everyone is talking football. Well, not everyone, perhaps. But befitting the nation's most popular sport, it generates a huge amount of conversation. According to my firm's research, there are 15 billion annual WOM impressions about football. In fact, over the course of the year, fully a third of all conversations about sports are about NFL teams.Which teams get the most chatter? That depends heavily on whether you measure via social media, or whether you also include the 90% of conversations that take place offline. With the NFL &#8211; as with so many areas of American life that we look at &#8211; it turns out the two conversations are quite different. As noted in my recent blog post , an ambitious academic research study that was recently released concludes, "Online data does not reflect well the offline behavior. Word of mouth is not channel neutral. One cannot automatically generalize the results from online to offline."According to my firm's TalkTrack research, which measures offline as well as online word of mouth, the five most talked about football teams over the past year are the Dallas Cowboys, the Green Bay Packers, the New England Patriots, the New York Giants, and the Chicago Bears. Taken together, these five teams account for a third of all NFL-related word of mouth. Add in the next five, as seen in the chart below, and you now account for 60% of all WOM.&#160;&#160;It is enlightening to compare this to the teams that are most "social" as represented by social media. A number of firms have published such a ranking, and one that caught our eye was by the communications firm, WCG, which recently published their W2O ranking in this infographic.Of the top five teams most talked about teams, only two are also among the most five most social online&#8211; the Dallas Cowboys and the New England Patriots. The Green Bay Packers are the second most talked about team in America offline and online, but they are only #17 in social media, a drop of 15 places in the rankings. The Giants drop 10 places in the social ranking to #14, and the Bears drop 16 places to #21.&#160;On the other hand, several teams do much better in the social media ranking than they do from a word of mouth perspective. The Jacksonville Jaguars are ranked #8 in social media, while they are #32 &#8211; dead last &#8211; in terms of word of mouth. That's a gap of 24 places, by far the largest difference between the two rankings. The gap is not quite as large but still sizeable for the #9 team in social media, the Houston Texans, who are the 22nd most talked about team.&#160;Why do these teams perform so much better online than offline? The level of effort and investment that teams devote to their social media presence may vary across the league. In the Jaguars case, one reason may be their initiative of a "Social League" campaign that assigns points and prizes to fans that support their team in social. This online engagement, however, has not translated into offline engagement, raising questions about the market-wide benefit of such campaigns.More broadly, these contrasting results are an important reminder that while social media is abundant and leaves a seductively easy way to measure digital footprint, it is generally not representative of the larger universe of consumer conversation. Ninety percent of word of mouth takes place offline, and these real world voices need to be listened to -- and activated &#8211; if businesses are to fully achieve the power and promise of social influence.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 email@example.com.Read all Ed&#8217;s MediaBizBloggers commentaries at WOM Matters.Check us out on Facebook at MediaBizBloggers.comFollow our Twitter updates @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.