Shake Shack ads haven't been plastered all over television, the subway or on radio.
In fact, according to Goldman Sachs' report on the burger chain, that's part of the plan for Danny Meyer's company post-IPO.
"SHAK does essentially no traditional marketing, but has a strong presence on social media, which speaks to its relevance among Millennials," the report says.
Relative to sales, Shake Shack's presence on Vine is massive relative to most of its fast-food competitors.
Goldman Sachs Shake Shack report
The same goes for Instagram:
Goldman Sachs Shake Shack report
It's not by follower. McDonald's has 491,000 Instagram followers, to Shake Shack's 154,000. It's about how social media presence relates to system sales, and the overall revenue of each company.
Shake Shack will make a little over $160 million in revenue this year, compared to McDonald's revenue approaching $30 billion.
As you can, the Shake Shack's food is incredibly Instagram-friendly.