The Long Tail Theory suggests that the Internet contributes greatly to the development of the niche market.However,some recent researches believe that the there is ready sale for popular products online.In order to verify the different performances of online vendors in the two types of markets,this paper conducts an analysis on the sales data of more than 641 thousand kinds of products sold by 791 shops on Taobao.The results show that online sales are influenced by such factors as reputation,product variety...