Sales of John Grisham’s latest book, “The Confession,” have reached a digital mile marker far faster than digital albums. According to an article at the Wall Street Journal, 70,000 of the 230,000 units sold in the first week were e-book sales. sold more e-books than hardcover versions of the title.

E-book readers are in their infancy compared to portable digital music players. So the fact that “The Confession” achieved a 30% digital share shows how book buyers have embraced digital formats at a faster rate than have music buyers. A couple years after iTunes Music Store went live, an album with strong digital sales like Kanye West’s “Late Registration” was pulling just 6% of sales from digital.

Even today, many mainstream albums don’t even achieve a 30% digital share seven years after the debut of the iTunes Music Store. Taylor Swift’s “Speak Now” and Darius Rucker’s “Charleston, SC 1966” both opened with a 27% digital share, according to Nielsen SoundScan. Sugarland’s “Incredible Machine” opened with a 17% share. Alternative rock albums tend to be higher – Kings of Leon’s “Come Around Sundown” opened with a 44% digital share, for example, and Bruno Mars’ “Doo Wops and Hooligans” debuted with a 40% digital share.

With higher e-book sales come fewer hardcover sales. The WSJ points out that Grisham’s publisher, Random House, cut its print run in anticipation of strong digital sales. The publisher printed 1.5 million units of “The Confession,” 400,000 fewer of his previous novel, “The Associate.”

As record labels well know, transitioning sales from physical to digital can bring lower revenue. sells the hardcover version of “The Confession” for $15.48, a sharp discount from the $28.95 list price.’s e-book version for the Kindle, however, is only $9.99. Barnes & Noble has a similar disparity between hard cover and e-book prices -- $15.92 and $9.99.

Even with this big first week for “The Confession,” the WSJ points out that digital book sales are still a small part of publishers’ revenues. From the article:

“While firm e-book numbers are hard to come by, the nation's largest publishers have seen steady growth this year in their digital sales even as bookstore sales remain soft. On Monday, Lagardere SCA's Hachette Book Group said that digital books accounted for 9% of revenue in the U.S. for the first nine months of the year. Digital book sales were so negligible last year that Lagardere didn't break them out in its financial report for the first nine months of 2009.”