The field of this research is a specific part of electronic commerce called group buying on the Internet or online group buying in terms of theoretical assumptions and key determinants of customers behavior in online group buying. The basic theoretical concepts of
customers decision making in online group buying are analyzed: social exchange theory, equity theory
and heuristic model. The basic characteristics of competitive environment are established and customer
behavior in online group buying is analyzed in terms of website performance and heuristic factors of
customer decision making within national markets of selected countries of the Western Balkans
