We develop a two-stage model for versioning products with respect to both vertical and horizontal attributes. At first, a firm positions its top-quality "flagship" product in a market with an imperfectly known distribution of tastes and reservation prices. In the second stage, the firm learns these consumer characteristics and has the option of extending its product line by versioning the flagship product using pure horizontal differentiation, quality degrading, or both. The firm's nonconvex versioning problem is solved analytically for the two-product case. We find that ex ante extending the product line through vertical differentiation is optimal for low marginal cost of quality (development cost); otherwise pure horizontal differentiation is superior. Given quasilinear consumer preferences and a uniform distribution of consumer characteristics, versioning with respect to both horizontal and vertical attributes is never optimal. Under delayed differentiation the optim...
Thomas A. Weber