Artificial intelligence is expected to become the dominant force behind digital advertising over the next few years, with Gartner forecasting that more than 70% of global advertising spend will flow through AI-influenced self-serve advertising platforms by 2028. The research firm said AI is rapidly transforming how campaigns are planned, bought, optimised and measured, reducing manual intervention while increasing automation across the advertising ecosystem.
According to Gartner, AI-powered advertising platforms are evolving beyond campaign assistance to become decision-making systems that automate audience targeting, creative optimisation, bidding strategies and budget allocation. The shift is expected to reshape the relationship between advertisers and media platforms as marketers increasingly rely on AI-driven recommendations instead of manually managing campaigns.
The prediction reflects the growing adoption of self-serve advertising tools offered by major digital platforms. Products such as Google's Performance Max, Meta's Advantage+ and similar AI-enabled solutions increasingly automate campaign setup and optimisation, allowing advertisers to define business objectives while machine learning systems determine the most effective delivery strategies.
Gartner noted that AI is making advertising more efficient but also introducing new challenges around transparency. As platforms assume greater control over campaign execution, marketers may find it more difficult to understand how decisions are made or justify media investments to business stakeholders. The increasing reliance on algorithmic optimisation is changing how campaign performance is evaluated and how media buying decisions are explained within organisations.
The firm's forecast comes as enterprises continue increasing AI investments across marketing functions. Gartner previously estimated that organisations worldwide will spend $2.59 trillion on AI in 2026, with enterprise adoption accelerating as AI becomes embedded across software, infrastructure and business workflows.
Marketing leaders are already allocating a growing share of budgets to AI technologies. Gartner's 2026 CMO Spend Survey found that AI accounts for an average of 15.3% of marketing budgets, although only 30% of organisations currently consider themselves mature enough to scale AI capabilities effectively. The findings suggest that while investment continues to rise, many organisations are still developing the operational capabilities required for enterprise-wide AI adoption.
The forecast also reflects the broader evolution of AI within marketing. Earlier this year, Gartner predicted that 60% of brands will use agentic AI to deliver one-to-one customer interactions by 2028, indicating that AI is expected to influence not only advertising operations but also customer engagement and marketing execution.
Industry analysts believe AI-powered self-serve platforms are particularly attractive because they lower barriers for advertisers while improving campaign efficiency. Small and medium-sized businesses can launch sophisticated campaigns without extensive media expertise, while larger brands increasingly use AI to manage complex, multi-channel advertising at scale. Automation is also enabling faster optimisation based on real-time performance signals rather than manual adjustments.
At the same time, Gartner cautioned that marketers should not treat AI as a complete replacement for human oversight. The research firm said organisations will need stronger governance, improved measurement frameworks and greater transparency to ensure AI-generated recommendations align with brand objectives and regulatory requirements. Maintaining visibility into campaign performance and decision-making processes will remain critical as automation expands across the advertising landscape.
The forecast underscores how AI is becoming central to the future of digital advertising. As self-serve platforms continue integrating advanced automation and generative AI capabilities, marketers are expected to shift from manually managing campaigns to supervising AI systems that execute media buying, optimisation and creative decisions. By 2028, Gartner believes this model will account for the majority of global advertising spend, marking a significant transformation in how digital marketing is planned and delivered.