Q: May I advertise my product’s advantages over another’s, stating his name?

A: This is permitted if the information is true and that you are careful to avoid geneivas daas (misleading) and lashon hara. For example, it would be misleading to compare your product equipped with optional add-ons against your competitor’s basic product, when he provides the same add-on features. To compare the low price of your basic model against the high price of his fully-loaded model is equally misleading. However, if you are running a sale you may compare your sale price to his full price if you note “sale” and “regular” price. The customer can easily check if the competitor is also running a sale now (C.M. 228:11).

Writing derogatory statements about your competitor is lashon hara. If you outperformed your competitor in a customer survey, you can advertise that, but if the competitor was rated dismally, publicizing his result is lashon hara. Even if information is readily available, it is still prohibited if your intention is to disparage him or gain from his failure (Chofetz Chaim Lashon Hara 2:3).