A friend tipped me off to Sara Bareilles, who recently got into iTunes' top ten titles with her debut, Little Voice. The Wall Street Journal's Jamin Brophy-Warren noticed Bareilles as well and uses her as a case study for the benefits of variable pricing.

Little Voice sold 14,000 units at iTunes in its first week of release. "Ms. Bareilles says the lower price was probably responsible for her strong digital showing," wrote Brophy-Warren, "which accounted for around 80% of her total sales." The album was part of iTunes "Next Big Thing" series of bargain-priced albums.

What Brophy-Warren surprisingly failed to mention in the article is that Bareilles' track "Love Song" was the free iTunes "single of the week" at the end of June. It was no doubt the combination of the free single and the low album price that helped push Bareilles to the top of the iTunes chart. A low album price alone would not have done it.

A free single and a cheap album is a winning combination. Unfortunately for labels and artists, there is a finite number of songs that can be anointed free singles of the week at iTunes. The "Next Big Thing" campaign is having an impact on participating artists, though not enough to push the albums into the top ten. Digital sales of Great Northern's Trading Twilight For Daylight, for example, rose 631% last week, while Mozella's I Will jumped 419%.