Due to the rise of technology and the quest for productivity, retailers continue to expand customer coproduction initiatives and companies therefore need to train customers for their roles during their visit. This research aims to compare the effects of proactive training (before experience and before customer request) vs. reactive training (upon request during the experience) on customers' ability to coproduce (script proficiency), the total sales value per customer, and customer satisfaction. Which is the best solution for training customers? This research proposes three main contributions. First, we define the concepts of proactive and reactive training. Second, this research proposes a new way of measuring coproduction by adopting the company's perspective. Third, with this method, we establish that proactive training is the only type of training that increases script proficiency, which in turn positively influences the total sales value per customer, but not customer satisfaction. However, reactive training is still important to avoid critical situations.