Previous research has yet to fully explore the mechanisms through which digital platforms shape the performance of tourism small and medium enterpirses (SMEs). This study, guided by the organizational learning theory, hypothesizes that engagement with digital platforms impacts tourism SMEs' business outcomes primarily through the enhancement of capabilities, specifically marketing and innovation. This study conducted an online survey involving 316 Bed and Breakfast (B&B) owners and supplemented it with semi-structured interviews of 21 owners. The findings reveal that both the intensity of participation (measured by the allocation of human resources to digital platform management) and the diversity of participation (indicated by the number of platforms used) positively correlate with business performance, specifically, revenue per available room. This effect is mediated by marketing capability. Additionally, our results emphasize the valuable role of social media platforms in elevating B&Bs' competitiveness. We provide both theoretical perspectives and practical suggestions based on our findings.