This study addresses a vendor's strategies to tackle its own installed base when selling a newly improved product. In particular, we investigate the optimal combinations of timing, pricing and product line strategies that the vendor can employ for selling its newly improved product in the presence of an installed base. We characterize the market with either a partly- or fully- covered installed base in terms of consumers' relative willingness to pay for the newly improved version and their relative payoffs from delayed purchase across periods. Different from the conventional proposition of...