The first three sales weeks of January yielded a striking trend on the Billboard 200: Each week, an emerging act's new album charted based solely on digital sales.

Thanks to favorable home-page exposure at the iTunes Music Store, free downloads, attractive pricing and a traditionally slow sales period, up-and-coming acts Erin McCarley, Company of Thieves and the Boxer Rebellion each debuted on the big chart.

Singer/songwriter McCarley released her debut album, "Love, Save the Empty" (Universal Republic), Dec. 30 exclusively at iTunes and bowed at No. 86 on the Jan. 17 Billboard 200. Wind-up Records rock act Company of Thieves released its first album, "Ordinary Riches," through iTunes Jan. 6 and debuted at No. 162 on the Jan. 24 tally. And unsigned British rock band the Boxer Rebellion released its new album "Union" exclusively at iTunes Jan. 13 and debuted at No. 82 on the Jan. 31 chart.

While none of the three albums remains on the Billboard 200 this week, their strong initial showings were a reminder of the market's continued transition to digital sales, as well as the formidable leverage that iTunes retains with consumers.

"It was just a matter of time before this type of thing happened for the first time and starts happening more often," McCarley's manager Michael McDonald says. "It speaks to shifts in the business, and it's certainly not the last we're going to see of it."

Along with their auspicious debuts, the three acts had another thing in common...

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