With more than 1 billion unique users a month, YouTube is quickly becoming the hottest entertainment destination, period.
Feel out of the loop? Here's a cheat sheet on 10 of the biggest YouTube stars out there, and why they're so famous.
No one gets more views than PewDiePie.
Swedish creator Felix Kjellberg uploads videos to his channel, PewDiePie, that show him playing video games while squawking in funny voices and commenting on the games.
Kjellberg is known for his over-the-top, profanity-laced reactions and goofy mannerisms, and his comedic personality brought him over 10 billion views last month -- a record for YouTube.
The 26-year-old made $12 million last year from ads and sponsorships; unsurprisingly, the young man has quit his day job.
2. Jenna Marbles
Jenna Mourey, better known by her YouTube username Jenna Marbles, made it big when she posted a comedy video called "How to trick people into thinking you're good looking" that showed the blonde giving a parody tutorial.
Mourey instructed viewers to "bleach the absolute s**t out of [their] hair," go tanning, wear contact lenses and cake on makeup. Her tell-it-like-it-is sense of humor struck a chord in fans. Now, Mourey has well over 15 million subscribers.
Creator Michael Stevens answers your burning science questions on his channel, VSauce.
The channel answers questions like, "Why do humans have two nostrils?" or "What does outer space smell like?" and has spawned several spinoff channels, including VSauce2, VSauce 3 and WeSauce, that cover different topics like technology or video games.
But the original VSauce channel remains the most popular, with nearly 10 million subscribers.
And don't think it's pseudoscience, either -- Stevens reads up on academic papers for his videos.
4. Bethany Mota
Move over, One Direction.
Teenage girls are crazy about Bethany Mota, the charismatic 19-year-old who creates YouTube videos about hair, makeup, fashion, DIY projects and other lifestyle topics.
Mota can't hit a mall without getting mobbed, and her fame extends far beyond YouTube: The teenager was on "Dancing with the Stars," and she even had the chance to interview President Obama.
Mota has said before that she is very shy and started her YouTube channel as a way to express herself.
5. Michelle Phan
Anyone who's looked up tips on creating the perfect smoky eye or how to imitate a celebrity's makeup (like Lady Gaga's look from a specific music video) has stumbled across Michelle Phan's channel on YouTube.
The beauty expert offers tutorials on basic tips, such as how to take care of your skin in the evening, but Phan is also known for her over-the-top videos that recreate makeup looks inspired by things like Day of the Dead sugar skulls.
The makeup artist is so popular that she has had partnerships with brands like Lancome and L'Oreal. She also founded the makeup company Ipsy, which sends out a cosmetic bag filled with samples to subscribers.
Phan was on this year's Forbes' "30 Under 30" list.
6. Superwoman a.k.a. Lilly Singh
Lilly Singh isn't your typical star: She's a self-proclaimed tomboy who has a penchant for baseball caps and sneakers. But her "realness" is what fans appreciate on her Superwoman YouTube channel.
Singh is known for making fun of her old-school Indian parents and creating parody videos that examine crushes, airplane rides, horror movies and everything in between.
Singh told CBS News that she didn't start growing a steady fan base until she opened up and showed her true colors.
"The second I started to be myself, my imperfect self, and show my flaws and point out my pimple and have my hair messy -- that's when I started to get success," she said.
7. Tyler Oakley
Tyler Oakley got his start posting videos of himself talking about his life and musing on his day -- sometimes they were silly, and sometimes they were self-reflective.
But soon, Oakley, who is gay, became an activist for gay youth. He is outspoken about LGBT rights and frequently talks about LGBT issues on his channel. Now, Oakley is one of the best-known voices on queer culture.
Oakley has interviewed the likes of Michelle Obama and One Direction, and frequently appears on TV.
8. Lindsey Stirling
Did you see Lindsey Stirling rock out with Dierks Bentley on the CMA Awards stage this year?
If so, you may have forgotten that the violinist had some very humble beginnings. Stirling got her start on YouTube, dancing, singing and composing her own songs. She's one of the most well-known musicians on YouTube and has more than 7 million subscribers.
Though she was once rejected from"America's Got Talent," she now has two YouTube Music Awards, two albums and a book deal under her belt. What is the musician up to next? Look out for a mobile game from Stirling in the near future.
9. Laura Vitale
There's a new Italian-American cook in town, and surprise: She's from New Jersey.
Laura Vitale and her husband run their YouTube channel, Laura in the Kitchen, together, and Vitale's videos show users how to make rhubarb crisp, ricotta pancakes, Nonna's stuffed calamari and many other dishes.
The recipes are easy-to-follow and Vitale's style is casual and approachable: Viewers won't be scared off by intimidating, complicated techniques. Who can't make one pot of spaghetti?
Vitale has more than 2 million subscribers and just published a cookbook called "Laura in the Kitchen." Vitale even has an upcoming TV show.
There's a sweet story behind Vitale's success: She moved to the U.S. from Italy when she was 12, and wanted to stay in touch with her Nonna back in her home country. She would call her grandmother every Sunday and go through the recipes her grandma cooked for Sunday suppers, and the two cooked together over the phone.
10. Cassey Ho
Who needs the gym when you have YouTube?
Cassey Ho is the creator behind Blogilates, where she teaches viewers different workouts along with healthy recipes and fitness tips. Ho's workouts have become so successful that her method, POP Pilates, will even be a class at 24 Hour Fitness gyms.
Ho also has a book called "Hot Body Year Round." Her workouts cover all of the body parts you want to hit, like if you want a move that will kick your butt into shape in just three minutes, and range from beginner to more advanced levels.