Abstract
Customer data enables online marketplaces to identify buyers’ preferences and provide individualized product information. Buyers learn their product value only after contracting when the product is delivered. I characterize the impact of such ex-ante information on buyer surplus and seller surplus, when the seller sets prices and refund conditions in response to the ex-ante information. I show that efficient trade and an arbitrary split of the surplus can be achieved. For the buyer-optimal signal low-valuation buyers remain partially uninformed. Such a signal induces sellers to sell at low prices without refund options, resulting in commonly observed practices of opaque sales.