So I found out yesterday that we sell a secret sandwich at Arby's that's not on the menu. It's called "Meat mountain" pic.twitter.com/4CaPCvSNFi — Chris Guy (@Chris_Guy1) August 21, 2014

On Monday, the Washington Post published an in-depth article about Arby’s business fortunes and marketing strategies, accompanied by a much shorter article about Arby’s Meat Mountain, an off-menu sandwich that contains eight types of meat—chicken tenders, roast turkey, ham, corned beef, brisket, Angus steak, roast beef, and bacon. Can you guess which story was more popular? The Meat Mountain story went bona-fide viral, garnering salivating coverage everywhere from Time and Business Insider to CNBC and Fox News.

The story of the Meat Mountain as it’s been told in the media thus far has been that it was a grassroots phenomenon—that it went viral all on its own. As Christopher Fuller, Arby’s vice president of brand and corporate communications, told the Post, Arby’s had started displaying a poster featuring a stack of every single meat they serve, and “People started coming in and asking, ‘Can I have that?’ ” But I was skeptical. Had Arby’s customers really clamored for the Meat Mountain of their own volition? Or had Arby’s headquarters engineered the story to get the low-cost marketing that comes with hundreds of thousands of social media likes and shares?

I decided to dig a little deeper into the Meat Mountain, to mine its mysteries and secrets. First, I emailed Arby’s manager of public engagement, Jason Rollins, to ask for more details about the supposedly grassroots origins of the Meat Mountain. Rollins responded:

Customers actually began requesting the sandwich with our team members, who in an effort to always “make it right” (our service mantra) with the customer; made the sandwich. We began hearing from our restaurants and fans in social that it was emerging as a secret menu item, so we let our restaurants know about it in case they were asked.

As expected, Rollins was toeing the company line. So I began perusing Twitter and Facebook to see if I could find any early examples of the “fans in social” he mentioned who were posting about this “secret menu item.” But, suspiciously, the only social media posts I could find that predated the Post article seemed to be from teenagers who work at Arby’s. When I asked them what inspired them to tweet about the sandwich, some wouldn’t speak to me at all, for fear of getting in trouble. One told me:

Another was more bold. Chris Guy, a 17-year-old who’s worked at an Arby’s in Pennsylvania for six months, agreed to answer some questions about how he first heard tell of the Meat Mountain.

“My first encounter with the sandwich was as I was working ‘front line’ (cashier) and a gentleman came to me and asked [can] I order the sandwich with ‘all the meats on it,’ ” Guy told me in an email. Confused by the man’s request, Guy suggested that the customer order a Triple Stack, which contains roast beef, roast turkey, and bacon. But the customer, Guy says, “insisted that his coworker got a sandwich with every single meat and pointed to a standing sign that had a stack of all our meats pictured on it.” Eventually, another Arby’s employee pointed Guy toward a new “Meat Mountain” button on the register screen and showed him how to make it.

Guy told me that the Meat Mountain first became widely available on Aug. 17, around which time an instruction sheet showed up in the kitchens of many of the chain’s locations. (Not all Arby’s sell the sandwich.) Guy’s introduction to the Meat Mountain occurred three days later, on Wednesday, Aug. 20. But Guy couldn’t tell me whether anyone had spontaneously ordered the sandwich before Arby’s had started distributing the recipe and adding Meat Mountain buttons to its registers, as the Arby’s VP had claimed to the Washington Post.

So I went back to Rollins, Arby’s PR guy, to press for more details. When and where had these organic pleas for eight-meat sandwiches occurred? Could he show me an example of the “fans in social” whose requests for the Meat Mountain had prompted Arby’s executives to give the people what they wanted? Could I talk to an Arby’s employee who’d fielded a request for the sandwich before Arby’s had let managers know about the recipe around Aug. 17?

At first, all Rollins would send me was a link to an Instagram post from this week, long after the Washington Post article was published. He also declined to put me in touch with an Arby’s employee. After I made it clear that I was looking for evidence of spontaneous Meat Mountain mania before the story broke out, he eventually sent me a link to another Instagram post, this time from July 30:

The post does indeed comprise an apparently organic request for the Meat Mountain. So maybe Arby’s story was accurate all along. After all, restaurant patrons make special requests all the time, and Arby’s customers tend to be people who like meat. As for Guy, he confirmed that he only tweeted about the Meat Mountain because he thought it was cool. “There was no mention from my manager or anyone else to advertise it on social media or anywhere else,” he said. “It was strictly out of amazement.”

But regardless of how much unprompted demand there was before Arby’s “let [their] restaurants know about it,” Arby’s public relations team has been extremely canny in fostering the growth of the Meat Mountain while making it appear that they had nothing to do with it. Even the Washington Post story, Rollins confirmed to me, happened when Arby’s approached the Post about the Meat Mountain, rather than the other way around. In other words, Arby’s has managed to have it both ways: The Meat Mountain is on a “secret menu,” but everyone who’s been on Twitter or Facebook in the last 72 hours has heard about it. And while the Meat Mountain was allegedly the unexpected outcome of a whimsical advertisement, Arby’s distributed the recipe and added it to computer registers before some of its employees had ever gotten an order for it.

Of course, the Meat Mountain might indeed have gone viral by genuine, unprompted word-of-mouth enthusiasm if Arby’s waited long enough. But as many other supposedly spontaneous “viral” stories have shown us again and again, these stories can be engineered, and they are more likely to blow up if you’re a big brand that can give them a little more beef.