And yet behold the king and queen of today's music video scene, taking over for MTV-era monarchs Michael Jackson and Madonna.
At their torrid mouse-click pace — in September, Bieber was getting 3.7 million views a day, Gaga 1.8 million — the singers will be the first entertainers to top 1 billion YouTube views each, Gaga by Oct. 25 and Bieber by Nov. 3, says David Burch of TubeMogul, which monitors online video traffic.
Contributing heavily to their staggering stats are Bieber's Baby, with 353 million views (with a playing time of 3:45, that's roughly 2,518 years of screen time), and Gaga's Bad Romance, which has tallied 291 million views (at 5:08, 2,832 years).
The distant runners-up? Jackson and Britney Spears, each with about 600 million total views.
"No one comes close to Gaga and Bieber in terms of compiling this sort of statistic in this short a time," Burch says. "Clearly, they are tapping into something big."
That would be a keen understanding of the interactive nature of today's media consumers. In contrast to the passive days of watching videos on TV or hearing songs on the radio, today's music fans can actively promote an artist through repeated viewings and forwarding videos to friends, says Monica Herrera, news editor at Billboard.
"Today's model involves keeping the content coming in short bursts and staying very visible with fans, compared to days when being unseen might be viewed as cool," Herrera says. "When you click on your mouse, you get to be with the star."
YouTube spokesman Chris Dale says that for many music fans, "clicking on a video is like a form of competition — the more they do it, the more they wind up helping their favorite artist," he says. "Bieber and Gaga have figured out that there's a core overlap between what they do and what this generation wants."
Video is central to the careers of both stars. Gaga's elaborate creations, which often enlist the help of divas such as Beyoncé, almost demand to be seen more than heard.
And Bieber literally owes his livelihood to YouTube: Amateur videos of him singing are what led to his being signed by R&B star Usher. It also appears the teen is angling for a career in front of the camera: He's playing a troubled teenager in episodes of CBS' CSI.
"Justin Bieber is the first teen phenomenon in the era of universal access" to stars, says Bob Lefsetz, author of music-industry watchdog blog the Lefsetz Letter. "He's showing that the Internet really is providing new opportunities for the music business.
"And the production values of (Gaga's) clips prove the music video is not dead."