There are three contributions of this study. First,with unique characteristics in
economic and physical property, the classic marketing models including 4P, 4C
and 4S have different conditions in applying to the selling of digital product.
Second, for each catagroities of digital products, the priority of suitability of
established marketing mix models is provided. Third, there is an interesting
finding that the less trialability a digital product is, the more promotional tools
it needs