Strategic Prompt Pricing for AIGC Services: A User-Centric Approach
Xiang Li, Bing Luo, Jianwei Huang, Yuan Luo
TL;DR
This work tackles prompt pricing for AIGC services by recognizing that users engage in a two-step decision process: selecting a GAI model and determining how many prompts to submit. By introducing a formal notion of prompt ambiguity and an Optimal Prompt Pricing (OPP) algorithm, the authors transform a bi-level pricing problem into tractable subproblems, revealing a non-monotonic relationship between ambiguity and prompt usage. Theoretical results characterize homogeneous and heterogeneous user behaviors and derive closed-form pricing insights, while experiments with a GPT-like model demonstrate significant platform payoff gains (up to 31.72% over baselines). The study highlights the importance of incorporating user strategies into pricing design to improve platform performance and user welfare in AIGC ecosystems.
Abstract
The rapid growth of AI-generated content (AIGC) services has created an urgent need for effective prompt pricing strategies, yet current approaches overlook users' strategic two-step decision-making process in selecting and utilizing generative AI models. This oversight creates two key technical challenges: quantifying the relationship between user prompt capabilities and generation outcomes, and optimizing platform payoff while accounting for heterogeneous user behaviors. We address these challenges by introducing prompt ambiguity, a theoretical framework that captures users' varying abilities in prompt engineering, and developing an Optimal Prompt Pricing (OPP) algorithm. Our analysis reveals a counterintuitive insight: users with higher prompt ambiguity (i.e., lower capability) exhibit non-monotonic prompt usage patterns, first increasing then decreasing with ambiguity levels, reflecting complex changes in marginal utility. Experimental evaluation using a character-level GPT-like model demonstrates that our OPP algorithm achieves up to 31.72% improvement in platform payoff compared to existing pricing mechanisms, validating the importance of user-centric prompt pricing in AIGC services.
