Sandwich chain Potbelly is testing its Facebook ads to see if they make people happy

“We’re a growing brand, but we’re relatively low on the marketing spend,” said Sherry Ostrowski, senior vp of brand at Potbelly. “The key is now where we need a new strategic update but also a new tactical plan.”

For Potbelly’s new campaign, “Feed Your Smile,” the brand and its agency Doner partnered with MSU to test its creative in a lab environment.

While test subjects view the social content, everything from their breathing patterns to heart rates to sweat glands to facial expressions is measured. Only if certain targets are met — people smile, their heart beats faster, indicating excitement, or other physiological responses — does the creative pass.

“We’ve known for a long time that self-reported data on how users feel about stuff like advertising can be biased, if not flawed,” said Marcus Collins, Doner’s executive director of social engagement. “So we worked with the lab to test the very foundations of the campaign.”

Potbelly, which has 400 stores around the world, also on Thursday launched a new tagline, “Feed Your Smile,” that focuses on the idea of happiness. The campaign includes a partnership with songwriters where 100 original songs will respond to people expressing unhappiness on Twitter. In the next few weeks, it will use third-party APIs to track where there are annoyances like traffic or bad weather and target people accordingly. So, if there is a downpour in Chicago on Friday, the Doner team might make social creative that will be served to people in affected neighborhoods.

We made you a little tune to brighten your day. #FeedYourSmile pic.twitter.com/zDQkchBveE

— Potbelly (@Potbelly) June 1, 2017

All that content will be tested in the MSU lab. “With the competitor set, you get outspent,” said Collins. “So we’re trying to just outsmart.”