The Source of Data Value: Consumer Disclosure, Access Design, and Platform Monetization

Digital marketplaces increasingly earn revenue from transaction commissions and seller-facing data services. Sellers may purchase data to increase revenue or avoid competing with an informed rival. We examine how consumer disclosure rights shape these motives and the platform's incentive to provide data. We develop a game-theoretic model of a commissioned platform, two differentiated sellers, and privacy-sensitive consumers. Data generates value through bilateral sales-revenue gains and competition threats arising from asymmetric access. Under mandatory collection, the platform can monetize defensive adoption, even when bilateral personalization reduces seller revenue. Under voluntary disclosure, anonymous purchasing and strictly positive privacy costs make unilateral disclosure unattractive in the baseline. Exclusive access thus yields no usable information, restores sellers' no-data rejection payoffs, and eliminates defensive fees. Profitable provision therefore requires nonnegative bilateral revenue gains. Under full fee extraction, sellers retain their no-data net profits. This revenue alignment does not guarantee welfare gains: additional transactions may benefit consumers, whereas segmentation in an already covered market can raise anonymous prices and reduce welfare. Capping anonymous offers at their no-data benchmark protects individual consumers and limits positive-mass provision to the transaction-creation region. Extensions consider access choice, heterogeneous privacy costs, imperfect identification, and limited contractual credibility. Platforms should evaluate data services based on both bilateral-use and seller-rejection outcomes, and sellers should distinguish revenue-enhancing from defensive investments. Regulators should distinguish equal-access rules from effective consumer control and monitor pricing in anonymous channels.