Online diaries are series of posts generated by consumers in chronological order to record their post-consumption experience over time. This paper empirically investigates whether providing follow-ups in online diaries affects the sales of professional services, and how this impact is moderated by the perceived risk and the quality of service. We find that providing follow-ups has a positive effect on the sales. The effect is weaker for high-quality service. Interestingly, this effect is asymmetric for service with high and low perceived risks. Our findings provide important implications for both platform owners and service providers.