The effects of free sample promotions on incremental brand sales

The authors present a model of free sample effects and evidence from two field experiments on free samples. The model incorporates three potential effects of free samples on sales: (1) an acceleration effect, whereby consumers begin repeat purchasing of the sampled brand earlier than they otherwise would: (2) a cannibalization effect, which reduces the number of paid trial purchases of the brand; and (3) an expansion effect, which induces purchasing by consumers who would not consider buying the brand without a free sample. The empirical findings suggest that, unlike other consumer promotions such as coupons, free samples can produce measurable long-term effects on sales that can be observed as much as 12 months after the promotion. The data also show that the effectiveness of free sample promotions can vary widely, even between brands in the same product category. Application of the model to the data from the two experiments reveals that the magnitude of acceleration, cannibalization, and expansion effects varies substantially across the two free sample promotions. These and other findings suggest that the model can be a useful tool for obtaining insights into the nature of free sample promotions.