Designing business models that take into consideration the role of advertising support is critical to the success of online services. In this paper, we address the challenges of these business model strategies and compare different ad revenue models. We use game theory to model vertical differentiation in both monopoly and duopoly settings, in which online service providers may offer an ad-free service, an ad-supported service, or a combination of these services. Offering both ad-free and ad-supported services is the optimal strategy for a monopolist because ad revenues compensate for the cannibalistic effect of vertical differentiation. In a duopoly equilibrium, exactly one firm offers both services when the ad revenue rate is sufficiently high. Furthermore, we find that a higher ad revenue rate may lead to lower service prices. Consistently across both monopoly and duopoly settings, such price reductions are more severe in the cost-per-thousand-impressions model than in the cost-per-click model. Our findings emphasize the role of advertising revenues in vertical differentiation and offer strategic guidance for monetizing online services.
We examine a platform's optimal two-sided pricing strategy while considering seller-side innovation decisions and price competition. We model the innovation race among sellers in both finite and infinite horizons. In the finite case, we analytically show that the platform's optimal seller-side access fee fully extracts the sellers' surplus, and that the optimal buyer-side access fee mitigates price competition among sellers. The platform's optimal strategy may be to charge or subsidize buyers depending on the degree of variation in the buyers' willingness to pay for quality; this optimal strategy induces full participation on both sides. Furthermore, a wider quality gap among sellers' products lowers the optimal buyer-side fee but leads to a higher optimal seller-side fee. In the infinite innovation race, we perform computations to find the stationary Markov equilibrium of sellers' innovation rate. Our results show that when all sellers innovate, there exists a parameterization under which a higher seller-side access fee stimulates innovation.