Our challenge was to launch Wendy’s Pretzel Bacon Cheeseburger (PBC) nationally in July 2013 to drive same-store sales growth. Growth could be achieved by adding incremental visits from existing customers and by stealing customers from other fast food restaurants.

Wendy’s also saw an opportunity to use digital to further engage millennial consumers by making the brand “cool” again, as well as continue to grow its social following and generate earned media coverage.

But it all started with what we observed early on during the launch in test markets.

When Wendy’s launched the Pretzel Bacon Cheeseburger in test markets, our social monitoring identified that people loved it to the point of enthusiastically expressing that love on Facebook and Twitter.

This inspired us to turn these virtual love letters into love songs.

In a series of original music videos that ran on Facebook, Twitter and YouTube, we took our customers’ love-fueled tweets and posts about the Pretzel Bacon Cheeseburger and turned them into love song lyrics that were professionally sung as over-the-top love songs, hashtags, misspellings and all. We called them Pretzel Bacon Cheeseburger Love Songs.

At the end of each video, consumers were encouraged to try the new cheeseburger and tweet and post their love for it for a chance to get their comment sung. Each week, new comments were collected, new love songs were scored, and a new video was rushed to production and released online. Our grand finale even starred multiplatinum boy band star Nick Lachey.

Taking an over-the-top tongue-in-cheek approach to these love songs showed that Wendy’s takes its food very seriously, but not itself. We didn’t give away discounts, but instead gave away “virtual fame” by citing our biggest fans’ comments in our love songs.

What started with some social listening in test markets ended with what Wendy’s calls the most successful product launch in its history.

The company reported a 3.2% increase in same-store sales while the cheeseburger was in market. What’s more, the campaign generated 2 billion PR impressions. Even investors took notice, upping Wendy’s stock by 31%.

Pretzel Love Songs (PLS) also helped engage consumers in the brand overall. PLS reached more than 85 million eyeballs, and Wendy’s saw 7.8 million social interactions with PLS Facebook posts alone. It’s no wonder Wendy’s Facebook fans increased by 315,000 during the 60-day campaign and Twitter followers increased by 153,000.