In high-volume customer support services (in sectors such as large e-commerce platforms, major telecoms, large financial institutions and global SaaS/IT service providers), AI systems may benefit from economies of scale, as per-interaction costs decline with rising volumes, potentially offering efficiency gains compared to human operations which require additional staffing, benefits, facilities and training. Although enterprise-grade deployment can entail significant upfront expenditure, estimates suggest that these may be recovered within a relatively short implementation period, depending on usage intensity.3 Once in place, AI agents can operate at around USD 0.25–0.50 per interaction – compared with USD 3–6 for human agents and up to USD 15 per interaction for complex tasks, or working overtime – suggesting substantial scope for variable cost reduction (teneo.ai, 2025[32]).
AI adoption may also reduce reliance on external business process services (e.g. customer support, data entry, payroll processing, translation, or IT services)4 and related agency fees, by enabling in-house execution of tasks that were previously outsourced. The best performing organisations report outsourcing cost reductions of USD 2 million-10 million annually and a 30% decrease in the costs of external creative or content generation, including translations, from switching to GenAI for tasks previously outsourced (MIT, 2025[45]; CMA, 2023[46]).5,6 In the audit sector, AI adoption has been linked to lower audit fees and reduced staffing needs, attributed to improved accounting quality and reduced information asymmetry. The authors interpret this as AI enabling more efficient audit and accounting processes, displacing routine labour and lowering variable internal costs (Lai, 2025[47]; Fedyk et al., 2022[48]). In knowledge-intensive activities, AI systems can accelerate design and development cycles and automate administrative functions, helping smaller firms to reduce unit costs and compete more effectively in digitally intensive sectors (Babina et al., 2024[49]; Gupta, 2025[21]).
AI capabilities can also be used across different domains, improving the return on upfront investments. For instance, the GenAI used in customer service can also be adapted for compliance monitoring, sales forecasting, or internal documentation. Access to third-party foundation models via APIs or open-source tools allows firms to deploy “plug-and-play” capabilities (e.g. chatbots, image generation, code synthesis) that can be adapted to specific use cases without training their own models (OECD, 2024[2]; Chui et al., 2023[22]). Such modularity may reduce fixed costs, shorten development cycles and lower the minimum efficient scale required to compete in AI-enabled service markets (Brynjolfsson, Li and Raymond, 2023[15]; OECD, 2024[50]; Gupta, 2025[21]). For instance, a start-up offering financial analysis tools can integrate a third-party generative model to provide natural-language query functionality (chatbots) to clients, without having first to train its own large-scale model (see (Yang et al., 2023[51])).
Such efficiencies may lower the cost of innovation and support entry into adjacent or previously unattainable markets, with indications of improved performance outcomes such as reduced defect rates, lower energy consumption and greater supply chain resilience (Calvino, Haerle and Liu, 2025[7]; Calvino, Reijerink and Samek, 2025[5]).
Modularity is not unique to AI. Many other, new general-purpose technologies, such as cloud computing, APIs, or Services-as-a-Service (SaaS) platforms have also enabled scalable deployment. Accordingly, the pro-competitive effect of AI may depend on broad, affordable and non-discriminatory access to these tools (OECD, 2025[3]; CMA, 2023[46]; Agrawal, Gans and Goldfarb, 2018[29]). Where such access is open, AI can enhance market contestability by enabling smaller firms to enter and scale in markets that were previously dominated by incumbents with proprietary infrastructure and large datasets. In the financial sector, Fintechs can use third-party AI models to assess creditworthiness using alternative data, bypassing the need for traditional credit scoring infrastructure (CGAP, 2024[52]) (see Box 3.). This may reduce scale advantages and allow firms to compete more on ideas, speed and customer insight rather than size.