Taylor Swift received four certifications from the RIAA in January, leading the list of country artists who reached significant sales milestones.

Swift's album, Speak Now has been certified quadruple platinum for shipments of 4 million units. Meanwhile, The Taylor Swift Holiday Collection, released in 2007, reached gold status this month for 500,000 units. Her additional certifications include a multi-platinum single for "You Belong With Me," which reached 4 million downloads, as well as "Ours," which earned gold for 500,000 downloads.

Platinum singles also went to Luke Bryan's "Do I," Lady Antebellum's "Just a Kiss," Jerrod Niemann's "Lover Lover" and Blake Shelton's "God Gave Me You."

In addition, gold singles were awarded to Jason Aldean's "Tattoos on This Town," The Band Perry's "All Your Life," Dierks Bentley's "Am I the Only One," Bryan's "Don't Want This Night to End," Brantley Gilbert's "Country Music Be Country Wide," Lady Antebellum's "We Owned the Night" and Tim McGraw's "Felt Good on My Lips."

Several country albums also received RIAA honors in January. Rodney Carrington's Greatest Hits climbed to platinum status, as did Scotty McCreery's Clear as Day and McGraw's Number One Hits. Johnny Cash's Best of Johnny Cash, released by Curb Records in 1991, arrived at gold status more than two decades after its release.

Beyond country music, Adele's 21 continues to soar with shipments of 6 million units. Meanwhile, Bob Seger & the Silver Bullet Band's Greatest Hits from 1994 rises to 9 million units, partially due to its recent availability at iTunes. The band's Greatest Hits 2 from 2003 also climbed to platinum status.