Disclosed is a method for increasing the conversion rate, or the ratio of the number of actual buyers to the number of site visitors, of an computer-implemented system such as an Internet e-commerce website. Shopping cart abandonment may be reduced though the disclosed method wherein filler items are suggested to the consumer in order to qualify the consumer for a promotional bonus, such as free shipping. By simplifying the consumer's task of selecting filler items, the consumer may be more likely to consummate the sale instead of abandoning the shopping cart to find a better deal elsewhere. In the event no suitable filler items can be identified, alternative promotions may be presented to the consumer, for example, reduced rate shipping.