This paper extends previous studies on quantifying the risk of misinforming by introducing models, which allow measuring the risk of misinforming in case of competing messages. These models are realistic representation of the market situation, where purchasing decisions are made based on the assessment of all available offers and selecting the one that meets at most the buyer's needs. The paper emphasizes the case of two competing products offered to a group of potential clients and studies the risk of misinforming and its effect on the purchase decisions. In addition, models for the evaluation of the risk of sellers are also proposed.