Danny Meyer and Shake Shack brass ringing this morning’s opening bell on Wall Street.

This morning, Danny Meyer's burger chain Shake Shack — once a seasonal hamburger stand operating a single location in New York’s Madison Square Park, growing into a 60-chain global sensation with 27 located overseas in a diverse range of cities including London, Istanbul and Dubai — went public. The stock is currently trading close to $50 a share, which values the company at close to $1 billion. Not bad for a venture that was originally created as a side project. But, as we know from the Postal Service, sometimes the professional aside can pay off big in the end.

This morning at 9:29 a.m. EST I tuned in to CNBC and had to take a quick photo of the opening bell for posterity. I’ve covered Meyer’s unique — and universally praised — place in the New York City restaurant scene for nearly a decade, and find today’s listing not just extraordinary for the man (Meyer is now personally worth over $400 million), but for fast food culture as a whole.

In the coming days some big questions will be asked. What does a speculated 450 additional Shake Shakes (by 2016) mean for the competition? This news on the heels of McDonald’s sudden removal of their CEO — coincidence? Other quesitons: Will Shake Shack add menu items (Meyer has long been in the barbecue game)? Will Meyer's team re-invent the concept of breakfast, which has long been a challenge for the traditional fast food businesses?   

In 2013, I sat down with Meyer and asked him about his biggest challenge in business: “The question I get asked is how I can sustain the culture as I grow,” he said. “The answer is, ‘What if that question is the wrong question?’ What if the question were, ‘How can we use our growth to advance our culture?’ That’s really what we’re trying to do.”

And, if this stock valuation holds and Shake Shack grows into the Chipotle and Taco Bell rival that some shareholders will be expecting, it looks like he’s on his way to advancing culture in a big way. Fast food hamburger culture, at the very least.