Life as a celebrity on YouTube, Vine and other social-media platforms may look like it’s all grins and giggles.

But behind the scenes, according to digital stars, the job of feeding the never-ending maw of the Internet can be a grueling, all-consuming occupation. And Internet creators must be constantly on alert to fan reaction to their work: The double-edged sword of instant audience feedback means the crowd can hurl insults as fast as they do praise.

“People think it’s people sitting around on a couch making money,” said Erin McPherson, chief content officer at Disney’s Maker Studios. “But it’s hard work. The level of professionalism (among top digital talent) continues to amaze me. It’s very impressive.”

Interviews with more than a dozen top digital creators, including Jenna Marbles, Shane Dawson, iJustine, Tyler Oakley, Michelle Phan and the tag-teams behind Fine Bros., Smosh and Epic Rap Battles, provide a glimpse into the process of how these stars produce content that resonates with their millions of fans — and what motivates them.

SEE ALSO: New Breed of Online Stars Rewrite the Rules of Fame

Most who garner huge Internet fanbases continue to spend long hours working to get their videos just right, and have achieved their status through years of consistently plugging away. “It’s a lot of staying up all night,” said Shane Dawson, who produces videos daily for ShaneDawsonTV and his other YouTube channels.

For Tyler Oakley — who has 4.9 million subscribers on YouTube for his ruminations on “sassiness and beauty and fabulousness” — rising to stardom has been a journey seven years in the making. “My whole YouTube career has been a slow, steady growth,” he said. “It took me five years to hit a million subscribers.”

And the job description encompasses more than being a homebody talking into a video camera. L.A.-based vlogger Joey Graceffa (3.8 million fans on YouTube) recently traveled to London for an appearance. He worked in a European vacation as well, which provided fodder for his channel (like “OMG! ALIENS ATTACK US IN ROME!”).

“There’s definitely a lot of work, and it can definitely get overwhelming at times,” he said. “It’s such a new industry. We are paving the way for what this new industry really is.”

SEE ALSO: Survey: YouTube Stars More Popular Than Mainstream Celebs Among U.S. Teens

On the other hand, the workload ebbs and flows, Graceffa added: “Some days, I’ll just spend all day watching Netflix.”

Not everyone has the entrepreneurial drive to achieve digital success, particularly because at first there’s no money to be made by tirelessly slogging away. “You’ve seen only so many people break out from this system, because you need a work ethic and a drive to take it to the next level,” said Benny Fine, who along with his brother Rafi runs The Fine Bros. channels on YouTube.

Maintaining a close bond with fans — core to the livelihoods of digital stars — is a nonstop requirement, and one that spans multiple social media. British fashion and beauty blogger Zoe Sugg, whose YouTube handle is Zoella, said she spends several hours every day checking comments and feedback on YouTube, Facebook, Twitter, Instagram, Tumblr and her blog.

“It’s like a full-time job to reply to people,” said Sugg, 24, who works with fashion multichannel network StyleHaul. “I’m really bad at shutting things off. I can’t remember when I’ve gone 24 hours without a social interaction.” Meanwhile, Sugg recently signed a deal with Penguin to write two books, which will be published in the U.S. under Simon & Schuster’s Keywords Press imprint; her first novel, “Girl Online,” is about a 15-year-old girl blogger whose identity is exposed after she starts dating a pop singer.

To Jenna Marbles, the main thing it takes to be a successful presence on the Internet is just that: “You have to be a presence,” she said. “You have to give a shit about what people are asking and want to know. Because if you don’t, you won’t last online.”

The 27-year-old Marbles regularly responds to fan-submitted questions Example: “Would you allow someone to spread Nutella on your booty?” (Answer: “Yeah, YOLO!”) She also tries to grow her 13-plus million fanbase via guest appearances on other YouTube shows.

But audience interaction is both one of the best things about the job — and one of worst, said Smosh’s Anthony Padilla. “The audience connection, because they can comment so quickly, it’s so instant and gratifying,” he said. “But you will get torn up. You feel bad if they don’t like it.”

Without the filter of traditional media, some digital creators have found themselves in hot water. For example, Vine star Nash Grier, who has 9 million followers on the service, was excoriated on social media by Oakley and others after he posted a six-second clip last month in which he screamed out a homophobic slur. (Grier subsequently apologized.)

Justine (“iJustine”) Ezarik has been on YouTube since May 2006, before Google acquired the vidsite. She has learned to be careful to not post anything she might later regret. “I am very conscious of things I tweet and say, because I know I have a wide audience, and a lot of them are young kids,” she said.

Ultimately, the challenge for Internet-media creators is to strike a balance between honesty and edginess, while not fanning online flames. “I don’t hold anything back — I don’t worry if people think I’m going to be weird or strange,” said Andrea Russett, 19, who is signed with MCN Fullscreen. The Indiana native, who moved to Santa Monica a year ago, has 1.5 million subscribers for her YouTube channel, GETTOxFABxFOREVER. “I love just talking to the camera and that people genuinely love what I’m saying,” Russett said.

The mantra of remaining “authentic” is echoed by many digital stars. “There’s an equation: You have to be true to yourself, because people can see if you’re being a character or emulating someone else,” said Oakley. He started creating YouTube videos when he went to college, as a way to stay in touch with high-school friends.

Machinima’s Sky Does Minecraft (real name: Adam Dahlberg) has attracted more than 10.2 million subscribers with his reviews, sketches and animations about the popular Minecraft game — something he’s fanatical about. “A major part of growing a large audience has to do with just being real,” he said. “As cliché as it sounds, being yourself is the main part.”

With the advent of personal Internet video-casting, a growing number of stars are able to turn their passions into profits.

Jayson Love, who lives in Billings, Mont., stands to earn a six-figure income playing videogames like action role-playing title “Dark Souls II” eight hours per day (or more) by webcasting his gameplay on his Twitch channel, “Man vs. Game.” The video streams on the channel are free for anyone to watch. Love makes money from fewer than 5,000 subscribers who pay $4.99 per month to engage with him in the live Twitch.com chatroom.

“It’s the childhood dream come true,” said Love, 34, who holds a bachelor’s degree in Japanese. “People say, ‘You should have your own TV show!’ That for me would be a big step backwards because I am truly so happy doing what I do now.”

While many big digital stars began as hobbyists, some have wanted to break into Hollywood all along.

The two guys behind Epic Rap Battles of History, Peter Shukoff (Nice Peter) and Lloyd Ahlquist (EpicLLOYD), originally launched the channel on YouTube in hopes that it would lead to bigger music and entertainment projects. “My goal was always to do what I loved for a living,” said Ahlquist.

ERB, which is affiliated with Maker Studios, now has more than 10 million followers. Their musical sketches (like “Rasputin vs Stalin”) have been viewed 1.2 billion times.

At this point, the duo have been approached by music labels, according to Ahlquist. But their income from YouTube means they don’t have a major economic incentive to sign such a contract, and they’re not willing to cede creative control of ERB. Said Shukoff: “Nobody tells us what to do except our fans…. With regular record labels, I saw too many things that turned me off.”

And even as digital creators mature their brands into sizable businesses, they’re still starring in their own videos and handling the heavy lifting themselves. Beauty-tips vlogger Michelle Phan has a production deal with Endemol Beyond USA, and sells her own lines of makeup and other merchandise. But she’s still largely a one-woman-band when it comes to creating content for her main YouTube channel (6.8 million subscribers).

“If I’m shooting a video, it’s just me, a videographer and a gaffer,” said Phan, 27. “For me, it doesn’t feel like a job. It’s just something fun I love doing.”