This article introduces the concept of motivating operation (MO) to the field of online consumer research. A conjoint analysis was conducted to assess the motivating impact of antecedent stimuli on online purchasing. Stimuli tested were in-stock status, price, other customers' reviews, order confirmation procedures, and donation to charity. The results indicate that the concept of MO is applicable to the analysis of the motivating impact of antecedent stimuli on consumer purchase behavior. The advantage of the concept of MO is, first, that it leads to greater understanding of the complex world of contingencies operating within the consumer behavior setting online. Second, the MO account is designed specifically to facilitate intervention as it is formulated in terms of environmental stimuli that can be manipulated directly. This is important for online companies that strive to increase economic earnings from their Web shops by means of increasing customers' conversion rates. (Contains 3 tables and 6 figures.)