Temp agencies’ steady incursion into education staffing: School, marketing, and supply teachers. Many schools have become dependent on staffing agencies to meet temporary staff needs. Supply teaching staff hired via these agencies have become important for schools’ activities and budgets, attracting extensive criticism. The teachers’ unions have been harsh critics of the staffing industry’s burgeoning role in education. The staffing agencies themselves believe that they can complement and help schools. This article presents an exploratory study of schools’ external staffing, seeking to better understand the phenomenon in relation to school marketing. Drawing on interviews and textual analysis, and using a genealogical approach, the article addresses questions such as: What types of problems and opportunities arise in connection with the external sourcing of school staff? The results identify divided opinions about whether these staffing agencies are cost-effective, and about the extent to which they advance or impede pedagogical development, competence, and security in schools.