While the effects of sport sponsorship are widely researched, many studies suffer from a lack of generalizability and are oftentimes cross-sectional, given the challenges inherent in the collection and analysis of longitudinal data. This study seeks to remedy these issues by analyzing a longitudinal, heterogeneous dataset comprised of more than 500 sponsorships of North American sport leagues spanning 14 years. Results reveal an 8% increase in brand recognition in the first year following the initiation of the sponsorship. However, lagged variables indicate that the effect is reduced significantly after the second year. A second analysis confirms that effects are generalizable across multiple leagues and sponsorship categories. These results contradict the prevailing assumption that investments in sponsorship necessarily need to be long-term, suggesting that effects on brand awareness are more immediate and that effectiveness wanes the longer a brand remains a sponsor, representing an important and novel managerial contribution.