It seems like everyone is laughing at Rebecca Black. But her universally mocked viral music video has become a business success story — and that’s no joke.

The 13-year-old has garnered millions of YouTube hits, thousands of  iTunes downloads and become a constant Twitter trending topic thanks to “Friday,” a song almost universally considered to be pretty awful. Her single even hit number 72 on Billboard’s Hot 100 chart, sandwiched between the kids from Glee and country star Kenny Chesney.

What makes this song so bad it’s good? Is it the prodigious use of AutoTune? Or Black’s intense lyrical debate about whether to sit in the front or back seat of her friend’s car? What about the equally confounding video — why is she waiting for the school bus if her friends are giving her a ride?

“Friday” has all the classic attributes of an “earworm” — also known as a song that gets stuck in your head, according to James Kellaris, a marketing professor at the University of Cincinnati who studies the influence of music on consumers. The lyrics are relatively simple, there’s a lot of repetition and “some odd incongruities, features that violate listeners’ expectations.

“There is also something social going on here that has relatively little to do with the music itself,” Kellaris continues. “When a crowd of onlookers stops to watch something, others will stop to see what is going on. If the crowd increases, it exudes sort of a gravitational pull. This seems to be happening on YouTube, with millions of viewers checking out what all the fuss is about.”

Even if that attention is focused on how bad the song is, the broad level of public awareness is what’s really important here. Recent research co-authored by Wharton marketing professor Jonah Berger found that negative publicity can actually make a positive impact on sales by giving previously unknown products a share of the spotlight. In investigating how book sales were affected by poor reviews, Berger and his co-authors discovered that, as time passes, customers “may not remember that something is negative. You may read a negative review today, and then a couple of weeks go by, and you might remember that you heard something about the book, but not remember exactly what you heard.” In those cases, the poor review becomes “free advertising,” boosting awareness with few repercussions.

So far, the “Friday” video has more than 42 million views on YouTube. About 63,000 listeners took advantage of the site’s “like button” to give it the digital thumbs-up. But a comparatively whopping 543,461 clicked the “dislike” button.

An erroneous Internet report sparked rumors that Black was making hundreds of thousands of dollars from YouTube views and sales of her song. She’s not doing quite that well — Billboard’s Glenn Peoples did the math and estimates that she’s making closer to $25,000 per week from track sales. But that’s not bad for a single most people claim (at least publicly) to hate. (Black told Jay Leno that she’s donating the proceeds from the music video to earthquake/tsunami relief efforts in Japan and to her school.)

“Consumers may purchase [‘Friday’] precisely because the song is bad,” says Wharton marketing professor Deborah Small.  “A bad performance can be funny, and people experience schadenfreude, or pleasure from the pain … of others. This particular video … appeals to teenagers, who can relate to the characters in the video.”

They can also relate to Black. “Although [teens] may aspire to be rock stars, they can envision themselves at [Black’s] level of stardom,” Small notes. “This is similar to the [reasons for] the success of much of reality TV.”

It remains to be seen if Black capitalizes on her 15 minutes of fame to become the next Justin Bieber — or if she’s destined to languish in one-hit wonder territory. But she might take note of a cautionary tale from a recent Knowledge at Wharton story about the rise and fall of fads, which warns of the challenges in keeping consumer eyes from wandering. Hot streaks, according to Wharton operations and information management professor Marshall Fisher, “are like an airplane. If it stops operating at a certain speed, it falls like a stone.”