Delivery speed is one of the most important factors influencing consumer decision-making in e-commerce. Retailers have responded by continuously decreasing their average delivery times. This trend towards faster delivery has led to the emergence of a new business model that is transforming online-to-offline markets by providing a new time-critical service: Quick commerce promises to deliver products to consumers within minutes, ensuring almost immediate gratification of instant consumer needs. The main objective of this cumulative dissertation is to provide a better understanding of delivery time in quick commerce and its impact on consumer behavior. To this end, the author presents three independent articles, which are nested in a general introduction and conclusion. Article 1 is a systematic literature review that establishes the foundation for the dissertation by reviewing consumer responses to waiting time in various settings. Article 2 investigates how deviations from communicated delivery times relate to consumer repurchase behavior in quick commerce. Article 3 examines how consumers' purchase intentions depend on both their motivation for the purchase and the product type in question. The results of this dissertation contribute to prior research by (1) synthesizing and integrating existing evidence on consumer responses to waiting times, (2) providing knowledge about the effects of late and early deliveries on consumer behavior in quick commerce, and (3) improving the understanding of two important purchase factors (purchase motivation and product type) that may moderate the effect of delivery time on consumer behavior.