100 & Single: LMFAO's Pair Of Chart-Toppers Suggest Stardom, Guarantee Nothing

​The national star-making machinery only begins to take you seriously when you command the field more than once. Just like, say, GOP presidential candidates, pop acts can't chart one strong number and assume dominance is permanently theirs. They've got to come back on top, week after week, survey after survey. (Even then, as Michelle, Rick, Herman and Newt learned the hard way, stardom is fleeting.)

So it goes for electro-pop duo LMFAO, who kick off 2012 at No. 1 on Billboard's Hot 100 with "Sexy And I Know It," their improbable second chart-topper.

At least, it seemed improbable a few weeks ago. Six months ago, they looked huge: The shufflin' smash "Party Rock Anthem"—a six-week No. 1 smash in July and August, and the year's No. 2 single—dominated the summer of 2011 and introduced an infectious dance. But then, so did "Macarena" in 1996. The only differences between Los Del Rio then and LMFAO now is about 30 years of age, six inches of hair-height, some barely concealed expletives and, now, a followup hit.

"Sexy And I Know It" was parked at No. 2 for seven long weeks in November and December, kept out of the penthouse by Rihanna's blockbuster "We Found Love." If LMFAO's followup hit had to lose out to something, it might as well be "Found." The Calvin Harris-produced club romancer spent eight weeks atop the Hot 100, more than any 2011 hit; it even beat Adele's "Rolling in the Deep," the top song of the year but only a seven-week No. 1.

But "Sexy" proved tenacious, actually growing in digital sales as the weeks went on and Rihanna's smash began to wane. Like a caucus candidate surging when it counted, LMFAO found themselves atop the Digital Songs chart just in time for the annual iTunes holiday-week bonanza.

(A followup to my last column, which considered whether Katy Perry could, British-style, ride the U.S. iTunes Christmas surge to the top of the Hot 100. Her "The One That Got Away" couldn't quite close the deal with song-buyers; its 157% sales surge, boosted by a B.o.B remix, was smaller than LMFAO's and only got the song as high as No. 3 on the big chart. So not only did her gambit fail, but she reportedly spent the week deciding to separate from her British spouse. Talk about Merry Old England letting you down.)

This holiday season, the annual Apple-fueled song sales boost came a little early, thanks to Christmas falling on a Sunday. With thousands of new i-device owners running to their computers on the last day of the Billboard tracking week, "Sexy And I Know It" racked up an eye-popping 395,000 downloads, the fourth-largest one-week total for any song in 2011. Accordingly, LMFAO finally marched to the top of the Hot 100 as their sales dominance overcame Ri's continued control of the nation's radio stations. ("Found" still leads all songs in airplay; "Sexy" is the third-most-played song at radio.)

So! LMFAO have gone from a goofy novelty act that began 2011 without a single American Top 40 appearance, to validated pop-radio eminences entering 2012 with a pair of No. 1 smashes. Stardom confirmed?

Maybe.