Also in 2004, Sparks co-founded MixUnit.com, an online mixtape marketplace that ultimately became one of the largest hubs for mixtapes on the internet. He often released his own mixtapes and bootlegs on the site, including a series dubbed "SmashTime Blends" and several "Get Familiar" volumes. Acts featured on his tapes have included, The Game, Snoop Dogg, Destiny's Child, T.I., Usher, Ciara, Fat Joe, Cam'ron, Kanye West, Jim Jones, Amerie, Ashanti, Ja Rule, Fabolous, and numerous others. The site helped mixtape DJs like DJ Drama and DJ Khaled accumulate a following. In 2005, Sparks produced the Re-Up Gang's "We Got It 4 Cheap" mixtapes (both "Volume 1" and "Volume 2"). The Re-Up Gang was composed of both members of the Clipse (Pusha T and No Malice) and two other rappers (Ab-Liva and Sandman). "Volume 2" is widely considered a classic, and it also popularized Sparks' vision of the "mixtape-as-album" format.