Confronted with an increasingly competitive landscape for credence services in the gig economy, workers on gig economy platforms are compelled to compete by configuring the service specification options on such platforms to enhance the visibility of their gig offerings. Motivated by a dearth of research on the effects of discrete configurations of service specification options on service quality and sales, this study builds on competitive repertoire theory to advance a research model that seeks to unveil how the volume, complexity, and heterogeneity of service specification option repertoires affect service quality and sales. We empirically validate our hypotheses with a dataset comprising 3,307 lifestyle-themed credence services from Fiverr, one of the largest e-marketplaces for gig economy in the world. We discover that repertoire volume is positively associated with both service quality and sales whereas repertoire complexity is only positively associated with service quality. Repertoire heterogeneity, on the other hand, is neither associated with service quality nor with sales.