At auditing a fair the measure and evaluation of the exhibitors’ distance is a important task and can be used for further promotion of the fair. In analyzing the attraction radius of different fairs one can discover some figures that may raise questions regarding a simple averaging of the attraction distances. According to the research of the author, the bias in the attraction radius can be caused by to factors: the size of the attraction region and the distance from the region’s business center. Authors explored the bias factors and suggest a correction method to remedy it. A theoretical correction model was applied to evaluate three agribusiness fairs. It is established that the corrected attraction radius gives more realistic result than the simple averaging of exhibitors’ distance.