Software startups operate in resource-constrained environments and under extreme uncertainty. Such challenges highlight the need for effective product feature prioritization, which is critical to the success of startups. This book chapter examines how software startups prioritize product features and explores whether this differs from the feature prioritization practices of established companies. We identify key factors that influence startup prioritization decisions by analyzing 171 survey responses from experienced product managers. Our findings reveal that startups prioritize cost-related factors and time to market (TtM) significantly higher than established companies. Furthermore, the results show that financially informed prioritization can serve as a critical runway management tool for startups. Therefore, startups that fail to integrate these considerations might face premature scaling, cash flow crises, and shortened runways. This book chapter contributes to developing an initial understanding of feature prioritization for startups, providing actionable insights to practitioners aiming to make sustainable product feature prioritization decisions.