As AI chatbots like ChatGPT increasingly rely on Reddit’s authentic user content for responses, brands have begun planting covert marketing disguised as genuine user opinions. Reddit is responding by using its own AI technology to detect and remove these deceptive posts, marking a new front in the evolving battle over generative engine optimisation (GEO).
- Marketers seed Reddit with fake opinions to influence AI chatbots.
- Reddit employs AI and human moderation to cut spam by 20%.
- GEO startups like Profound gain high valuations amid the trend.
What happened
Brands have increasingly adopted a strategy of planting fake posts and comments on Reddit that appear to be genuine user opinions, aiming to manipulate AI chatbots like ChatGPT into quoting these as authoritative recommendations. This practice is part of a larger trend called generative engine optimisation (GEO), where marketers seek to influence AI outputs similarly to how traditional SEO targets search engines.
Reddit, whose content is highly trusted by AI systems and serves as a frequent citation source for chatbots, has recognized the threat posed by these deceptive marketing tactics. Leveraging advanced large language models, Reddit has enhanced its spam detection systems, identifying and removing approximately 25,000 suspicious posts and comments daily in early 2026. These efforts have decreased user exposure to such content by around 20% compared to the previous year.
Why it matters
The shift toward conversational AI as a primary information source changes how brands approach online visibility. Instead of optimizing for search engines, marketers now focus on influencing AI-generated answers through platforms like Reddit, exploiting the platform’s reputation for unfiltered human conversations. This new arena of generative engine optimisation challenges the integrity of AI-driven recommendations and user trust in the platform’s authenticity.
Reddit’s use of AI-powered detection tools alongside ongoing human moderation demonstrates the complexity and scale of combating this evolving form of digital marketing manipulation. The battle highlights an emerging ecosystem where technology and human oversight must cooperate to maintain the reliability of widely consumed online content, especially as AI models increasingly depend on such data to inform their responses.
What to watch next
As marketers refine their GEO strategies and continue to push content optimized for AI chatbots, Reddit’s countermeasures will likely evolve further in sophistication and scale. The ongoing cat-and-mouse dynamic suggests that new tactics in AI content detection and moderation will be critical for platforms reliant on authentic user-generated content.
Investors have already recognized the commercial potential of GEO, with startups like Profound reaching valuations over $1 billion by developing tools that help brands gain visibility in the AI era. How regulatory frameworks, platform policies, and AI technologies adapt to curb stealth marketing will shape the future landscape of digital marketing, user trust, and AI information quality.