Amster is president of Betsy Amster Literary Enterprises. A former editor at Pantheon and Vintage, she has been described in the L.A. Times as "a dogged prospector of the city's literary talent." Her clients include novelists Christopher Noxon, María Amparo Escandón, and Joy Nicholson; MacArthur fellow and urban farmer Will Allen; James Beard Award winner Kim Boyce; popular historian Margaret Leslie Davis; and bestselling research psychologist Elaine N. Aron.