Digital track sales fell 5.7 percent from 1.34 billion units to 1.26 billion units while digital album sales fell 0.1 percent to 117.6 million units from 2012's 117.7 million, Nielsen SoundScan said.
By the second half of 2013, music executives began to concede ad-supported and subscription streaming services were hampering digital sales, Billboard said.
Overall album sales fell 8.4 percent on the year to 289.4 million units from 316 million in 2012. CD sales declined 14.5 percent to 165.4 million units, down from 193.4 million; however, vinyl continued its rebound, rising to 6 million units from 4.55 million in 2012.
iOS 8 has a "killswitch" to help lower theft