Chance the Rapper performs at the 2014 Made In America Festival

Chance The Rapper performs on the Dylan Stage during day 2 of the 2014 Budweiser Made in America Festival at Los Angeles Grand Park on August 31, 2014 in Los Angeles, CA.  

Christopher Polk/Getty Images

When Chance the Rapper dropped his collaborative Donnie Trumpet & The Social Experiment album Surf on iTunes for free last week, he did so modestly as an out-of-the-blue surprise not even bearing his name. But that didn't stop it from making a big impact. 

Chance the Rapper's Experimental Album 'Surf' Has Arrived on iTunes…and it's Free

According to the Chicago MC, who tweeted the iTunes download figures Friday, Surf racked up 618,000 full-album downloads in its first week and more than 10.1 million single track downloads. 

 

Though it's not a fair direct comparison, it's worth noting A$AP Rocky moved 146,000 equivalent album units in the week ending May 31, according to Nielsen Music, with his Billboard 200 chart-topping At.Long.Last.A$AP. Of those, 117,000 were through traditional album sales and the rest were by track equivalent albums and streaming equivalent albums. 

Review: Donnie Trumpet & The Social Experiment Aim To Melt Your Cynicism On 'Surf'

Chance also said that the album will remain free forever -- good news for new and future fans.