Abstract: The advertisement of an enterprise not only promotes its own market demands, but also influences the market demand of its competitors’ products, which is called the Spillover Effect of Advertisement. Previous studies have found that strong brands’ advertising competition cause spillover effects on weak brands). This research extends current studies by examining the underlying mechanism using two experiments. Study 1 explores several mediating and moderating variables. The mediating variables include involvement of a strong brand, perceived product quality, and changes of market share. The moderating variables include product life cycle and product homogeneity, attitude towards advertising, and consumer task orientation. Study 2 examines the overall distribution rule of the spillover effect of strong brands’ advertising competition on weak brands. We focus on the periods of product growth and maturity. In conclude, we unravel the mechanism and overall distribution rule of strong brands’ advertising competition, which will enrich the theory of spillover effect and advertising effect.

Key words: advertising competition, spillover effect, consumer involvement, perceived product quality