He is best known as the chief executive officer (CEO) of Speedway Motorsports, LLC (SMI), an organization that owns or operates 11 racetracks across the United States.
Initially wanting to train to become a doctor at the University of North Carolina at Chapel Hill, he later dropped out and joined his father's company, working at the Charlotte Motor Speedway's marketing team as a sales associate.
In contrast to his father, Speed Sport writer Keith Waltz considers Marcus to be "not as boisterous or flamboyant".
Marcus has drawn praise for a focus on fan experience and interaction and for revitalizing the North Wilkesboro Speedway, one of NASCAR's founding tracks.
However, his tenure has seen continued decline at SMI racetracks despite numerous changes formulated to increase attendance, along with criticism from drivers and media outlets for repaves of certain tracks.
[3] In his off time during high school, he worked as a volunteer at the Charlotte Motor Speedway, doing numerous jobs, including grass maintenance, painting walls, and picking up trash.
[5] While working at Charlotte Motor Speedway, he frequently came into contact with the track's general manager, Humpy Wheeler, who he later stated on an episode of The Dale Jr. Download that he was "phenomenally impactful" to him.
[8] On May 21, 2008, Humpy Wheeler announced his departure from the speedway that was later revealed to be due to internal disagreements with Bruton Smith over the last several years,[9] a decision that was seen as a surprise within the NASCAR landscape.
[12] Within his first year, SMI, mainly due to the consequences of the Great Recession, oversaw a sharp decline in revenue and the company's stock price.
[14] The next year, Smith announced the creation of a Christmas lights drive-thru show at the speedway, one of the biggest in the country at the time.
[15] By the end of that year, The Charlotte Observer writer Ron Stodghill wrote in an opinion piece that "the guy seems to have a surprisingly firm grip at the wheel... [he] is emerging as a passionate leader".
[19] The next year, he announced intentions to renovate Charlotte Motor Speedway,[20] along with a statement that said that the Smiths were interested in buying the Carolina Panthers, a National Football League (NFL) team.
[21] In late 2016, Marcus and Bruton made a bid for a Major League Soccer (MLS) expansion team in Charlotte with support from local business leaders.
[38] On October 24, Katherine Peralta of The Charlotte Observer reported that the effort was "officially dead" as an agreement for a combination of private and public could not be reached by December, the deadline for the MLS.
[39] By November 30, when the MLS narrowed its shortlist to four cities, Charlotte did not appear, officially killing the Smiths' bid.
[62][63] Marcus married Cassandra Anne Mitchell on June 8, 1996, in Charlotte, North Carolina at the Central Church of God.
[2] Marcus, compared to his father, Bruton Smith, has been described as "not as boisterous or flamboyant" by Speed Sport writer Keith Waltz.
"[2] He has drawn praise for a focus on fan experience at SMI's tracks, with NASCAR journalist Jeff Gluck remarking, "fans feel so comfortable engaging Smith in conversation when he walks around an SMI track that he has been known to run late for his official duties... And during internal meetings, Smith will sometimes instruct employees to make whatever decision is best for the customers".
[66] When the Atlanta Motor Speedway was announced to be repaved to tailor to produce pack racing, Denny Hamlin stated in a Twitter post, "[SMI] has reconfigured Texas, Kentucky, Bristol with 0 driver input.
[67] Hamlin later criticized Smith in Twitter posts for a repave on the Sonoma Raceway in 2024, which had seen the newly-paved asphalt in the track's 11th turn come apart.