The source material consists of excerpts from Episode 600 of "The SDM Show," hosted by Rob Cairns from Toronto, Ontario, which focuses on various business, life, and digital marketing topics, particularly concerning WordPress. This landmark episode celebrates the achievement of 600 podcast episodes, which began in 2010. The episode features Cairns thanking his regular co-hosts, guests, and listeners, and includes numerous congratulatory messages from community members and friends recognizing the milestone, dedication, and quality of the show. Cairns concludes the episode by thanking his inspiration, Tiz Marrone, for helping him through a serious illness, and dedicating the show to his late father, Bruce Cairns, and his mother, Anne.