Relationship marketing (RM) has emerged as one of the dominant mantras in business strategy circles, though RM investigations often yield mixed results. To help managers and researchers improve the effectiveness of their efforts, the authors synthesize RM empirical research in a meta-analytic framework. Although the fundamental premise that RM positively affects performance is well supported, many of the authors' findings have significant implications for research and practice. Relationship investment has a large, direct effect on seller objective performance, which implies that additional meditated pathways may explain the impact of RM on performance. Objective performance is influenced most by relationship quality (a composite measure of relationship strength) and least by commitment. The results also suggest that RM is more effective when relationships are more critical to customers (e.g., service offerings, channel exchanges, business markets) and when relationships are built with an individual person rather than a selling firm (which partially explains the mixed effects between RM and performance reported in previous studies).