Generative AI (GenAI) is at the center of global hype and has been argued to transform knowledge work, including software engineering (SE). However, the field is still nascent. Companies are still exploring use cases, new tools are constantly emerging, and good practices are still missing. Although much research on the topic has recently been published, the practical applications of GenAI as a research area are still emerging, and research focusing on software startups is currently lacking. In this chapter, we use existing research on software startups and recent research on GenAI for SE to discuss the promise of GenAI for software startups. By highlighting and synthesizing findings of existing research from these two fields, we (a) argue why the problems currently associated with GenAI adoption and use are not as relevant for software startups, resulting in startups being in an advantageous position; (b) argue why, based on startup literature, GenAI is particularly useful for software startups; and (c) list current industry use cases based on existing research and discuss practical considerations related to GenAI adoption.