Product sampling is a popular product promotional strategy that emphasizes providing free product trials to new customers. This study aims to investigate the impact of different product sampling campaign characteristics (stimulus, i.e., free sample quantity, free sample diversity, and advertising information quality) on consumer cognitive and affective reactions (organism, i.e., perceived diagnosticity and perceived reciprocity) and consumer loyalty (response, i.e., product purchase intention and product rating). By collaborating with a leading Chinese beauty and care product sampling platform, we distributed the questionnaires to platform users who were actual free sample receivers and collected campaign information. Both subjective and objective data were collected to empirically test the research model. Our major findings suggest that perceived reciprocity has a positive and significant effect on product rating, but it does not affect consumer purchase intention. In contrast, perceived diagnosticity positively affects consumer purchase intention while it does not affect product rating. Research findings are discussed and are expected to enrich the product sampling-related literature and contribute to both academia and practice.