John left Brown University when he was cast in Universal's sequel to Jaws, Jaws 2 and continued to work as an actor for the next 6 years. After a brief hiatus from the entertainment business in which he worked on the US Senate staff for freshman Sen. John Kerry and helped run a presidential campaign, he began work with Boston sports attorney Bob Woolf who had built a significant practice representing professional athletes. John ran the music business management department and spent most of his time on a developing local act: New Kids on the Block. Within several years the company grew and he was sent to Los Angeles to open an office there with an emphasis on working with other established and developing acts. When he left the company in 1992, the firm was also working with Boyz II Men and Marky Mark & the Funky Bunch.

John became the general manager of Paisley Park Records, a joint venture between the artist Prince and Warner Bros. Records. After Prince, he formed a new venture with his partner, Qadree El-Amin. Southpaw Entertainment was a full service management company. In its early years it primarily focused on the management of Boyz II Men, but after the record-setting success of the 12X platinum "II" album, the company took on new clients. Over the years, Southpaw also handled the careers of Janet Jackson, Vanessa Williams, Brownstone and Blackstreet, among others.

As the new millennium dawned, John left Southpaw to take a position as an Executive Vice President of Overbrook Music, a music label as well as a full service management company owned and operated by Will Smith and his partner, James Lassiter. The company released the multi-platinum-certified soundtrack for the film Wild Wild West as well as the gold-certified soundtrack for the film Love and Basketball. In addition to Will, the company also managed Robin Thicke, Ginuine, Jordan Knight Deborah Cox , singer/songwriter Javier Colon and singer/songwriter Maria.

Since 2007 John has been at Hill Holliday where he runs a division that focuses on creating branded content and identifying and nurturing innovative partnerships in television, film, print and online.