Ten percent of Americans use Twitter, but a whopping 43 percent say they hear Twitter mentioned "almost every day," according to new data from Edison Research.  A big reason for Twitter's visibility is the prevalence of hashtags on TV, including in ads. Luxury automaker Audi has been an early, frequent and successful player in the hashtag space, so we asked the brand's senior social-media manager, Andy White, why it's worth investing so much energy in a social network that 90 percent of Americans aren't even using. For his take on the past two Super Bowls and how Audi turned one fan's comment into one of Twitter's most successful hashtag campaigns, check out the Q&A after the jump.
Q: In 2011, Audi was the first brand to use a Super Bowl ad hashtag, #ProgressIs. In 2012, it used #SoLongVampires. What were the metrics of success for these campaigns? Were there any results you didn't anticipate?
A: We had multiple metrics for social going into the event—such as YouTube views, Facebook activity, crack the top 5 in the Facebook/USA Today Ad Meter, etc.—but our key metric for the hashtag (outside of a baseline number of mentions) was simple: Curate and cultivate real-time dialogue and conversation. From that foundation, multiple metrics/wins arose that we could never have planned for, such as becoming the most-mentioned hashtag of the Super Bowl, and generating four globally trending topics.
Q: Many brands are reluctant to use hashtags in ads because they're afraid to dilute their call to action and would rather feature a website. Is a hashtag a strong enough call to action to stand alone?
A: For us, this was never a discussion; it was always the hashtag. The Super Bowl is [about] conversation and engaging in naturally forming dialogues that arise from a thought starter, which in our case was the hashtag on the spot.
We take the opinion that it's not natural for viewers to be directed to a URL while sitting and watching the No. 1 cultural event of the year. This is a social event, and viewers are being social. They're tweeting and checking in in record numbers, year over year. We have found that audiences are receptive to social overtures, and social is increasingly becoming a very natural CTA.
With such a huge broadcast, this may be a viewer's first-ever touch point with Audi. We treat that first touch point as just one step on a very long purchase funnel that may result in a car purchase—or it may result in a new aspirational fan, one that will take our future messaging and run with it to their own social graphs. Both of these goals are our social holy grails.
Q: Similarly, brands often view Twitter as too narrow an audience to focus on, when Facebook and YouTube have such larger user bases. What's the argument for focusing on Twitter?
A: We did have YouTube components to our overall social Super Bowl strategy; the spot premiered before the event on YouTube, for example. We maintain, however, that to tap into that live, as-it-happens cultural zeitgeist, Twitter is the medium in which it's best to reach, respond and be proactive.
Q: Critics say the results of TV ad hashtags are too short term, creating a brief spike in mentions but having little lasting impact. What's your take? Is it about amplification more than creating a long-term conversation?
A: This depends on the advertiser and whether or not they have a medium- to long-term commitment to the hashtag and to the conversation. With Audi, we monitor multiple threads of conversation simultaneously and have that commitment to follow through. Two examples:
#ProgressIs was our hashtag we launched in last year's Super Bowl. We extended the life of this tag through additional advertising, plus curating an ongoing dialogue online. #ProgressIs for Audi had some presence online for most of 2011.
#WantAnR8. This hashtag, originally started by one of our followers, was initially organic and then supported by us with paid ad dollars. It recently was featured in a nationally run TV advertising campaign,  the culmination of over a year of content social messaging. This hashtag is now utterly synonymous with Audi social.
To see more results from Audi's social-media efforts, check out Andy White's list of brand accomplishments on his About.me profile. 
While Audi isn't the only luxury automaker embracing Twitter, it's clear that the brand's efforts have vaulted it soundly above most of its peers, second only to Lexus. Check out AdFreak's comparison chart below to see how major luxury brands compare in terms of Twitter followers: