Indeed, some AMAs have gone better than others, with results correlating not only with the popularity of the star involved, but how willing they are to play along with dedicated redditors — who are smart, silly, eccentric, and, above all else, fiercely uninterested in being condescended to with brief, canned answers.

"The biggest piece of advice I give people is that it should be fun," Martin says. "If I'm talking to a publicist, if the person doing it isn't going to have fun, then they shouldn't do it. It's not for everybody. Ideally, this is at least more interesting, if not more fun, than your typical press junket. The other thing I tell them is that there are no rules."

True: Seth Rogen and Evan Greenberg discussed everything from their fathers' advice on strippers to their favorite weed in a chat that was peak Reddit. Arnold Schwarzenegger posted his responses in links to hand-scrawled notes; Snoop Lion (né Dogg) offered a flurry of short, to-the-point answers ("How much do you smoke in a week?" "81 blunts a day x 7"); Elijah Wood gave a rundown of his favorite records and spoke at length about his experience on the Lord of the Rings films; Ellen Page declared that her favorite juice is tequila; and Louis CK revealed that "I am blowing Ewan Mcgregor right this second."

"Clients love being able to answer questions (which no offense are sometimes better than the ones professionals ask) directly from the fans," Lewis Kay, the PMK●BNC publicist/VP who represents a litany of comedy stars, like Louis CK and Amy Poehler, told BuzzFeed in an email.

"I just think that anytime you engage fans directly they are more likely to support your latest project." Kay adds. It's an important point, because though Bruss says ID doesn't see AMAs as promotional tools, the chats generally come ahead of a new project's release. For all its quirks, the AMA has become, for some, another stop on a press junket, scheduled to raise awareness for a new movie, TV show, or album.

Rogen and Goldberg did their AMA just days before This Is the End hit theaters, Grenier was there on behalf of his documentary How to Make Money Selling Drugs and comedian Amy Schumer has one scheduled for July 1, the day before the season finale of her show on Comedy Central. Louis CK's chat — a return engagement after previous succeses — earned major coverage ahead of his HBO special in April, while Elijah Wood made a major dent in publicity for his indie film Maniac.

It's also clear that the AMAs work best when someone is not just game to answer questions, but has a firm handle on the audience that they're addressing.

"I'm not terrified. I'm kind of preparing myself. I'm going to be in a good place when I do that," Schumer jokes. "I feel like I've been in a good place and not too sensitive for a while now. People have been pretty good, but on reddit of course, it's total sea creatures coming out from their parents' basements. Oh, and I promise you I'm not worried about making them feel satisfied."

In a sign of just how established the site has become, Reddit just hired Victoria Taylor, a former ID employee, to serve as its director of communications.

"One of my favorite things in helping introduce interesting people and their teams to the concept of AMAs has been seeing them get excited about reddit," says Taylor, who works to help book and facilitate the conversations. "I remember the first AMA I suggested — which was actually with a medical expert answering questions about cardiac arrest and CPR — and how incredible it was to see the transformation in how they saw reddit before and afterwards."

Often, there are structural advantages that help celebrities succeed with their chats. Community, NBC's cult favorite sitcom, has a massive fan base and subreddit on the site, and when the show came back in March, its writers held an epic AMA.

The conversations can be difficult to follow, given the site's tiered comments sections that oftentimes bury answers beneath piles of other responses. But in a way, that helps amplify the AMAs' reach, as other sites rush to scour the transcript for the best bits and aggregate them into their own posts. There is also a helpful schedule of upcoming celebrity and notable personalities holding AMAs on the side of the section's home page.

"Reddit AMAs work because they are authentic, unfiltered and 100% up to the talent in terms of which questions to answer," Bruss explains. "They are not going to give you their home address, but they will engage as personally as they are comfortable... Gerry Butler was so blown away by the experience he recorded a separate thank-you video for the community that was completely unexpected and took on a life of its own. And recently Hans Zimmer was having such an incredible experience answering questions that he began sharing deeply personal stories related to his music inspirations that he's never really discussed publicly."

Those sort of personal admissions are key to the success of these chats. Social media like Twitter, Instagram, and Facebook has allowed celebrities to take fans inside their worlds like never before, but even then, they have complete control over their image. That's not completely the case with AMAs.

"Talent needs to open to this kind of engagement and be willing to answer unfiltered questions," Bruss notes.

The gold standard of cautionary tales occurred last year, when Woody Harrelson took a moment out of his junket schedule to talk about his indie cop drama Rampart. He was determined to keep the conversation on the movie, ignoring anything personal and steering off-topic inquiries back toward his unsettling — though, to be fair, critically acclaimed — film. It was so disastrous, with clipped answers and increasingly angry readers, that redditors began to openly berate Harrelson's publicist, who they figured was responsible for getting him signed up for the site in the first place.

Here's how bad it got: The top comment on the AMA is now the suggestion that the publicist "will be holding the toilet paper for Woody Harrelson while Harrelson takes a huge shit on his chest."

Strangely, one of the questions Harrelson did engage was about rumors that he crashed a prom and took a student's virginity, and the story took on a life of its own.