Large sunk costs of development, negligible costs of reproduction and distribution and substantial economies of scale make information goods distinct from physical goods. Consequently,how to take advantage of the specific characteristics of information goods is an important managerial problem. Price discrimination and product differentiation are common ways this issue has been addressed. In previous literature, vertical differentiation and related pricing strategies have been researched in contexts such as nonlinear utility functions,network externalities, competition and anti-piracy. Little attention has been paid to the relationship between market segmentation and product differentiation. In this paper, we emphasize the interaction of market segmentation and product differentiation as we believe that any product differentiation must be based on existing market segmentation. In our model, we treat vertical differentiation as a special case of horizontal differentiation, and we model the interaction between different market segments showing the differences in product differentiation strategies when moving from horizontal to vertical differentiation. We find that it is always sub-optimal to differentiate information goods if the market is not fully differentiated or if characteristics of the information goods are not specifically designed for certain market segments. We divide characteristics of information goods into four categories according to the ease of differentiation and design guidelines for firms to differentiate their goods based on these characteristics. We further provide guidance on whether to merge one or several versions when costs for versioning information goods are significant.