Reddit has emerged as the leading source of information for artificial intelligence models in 2025, accounting for approximately 40.1% of AI knowledge citations. According to data collected by Profound and highlighted in Reddit's shareholder letter, the platform's extensive human conversations covering a wide range of topics make it a critical backbone for building effective AI systems. Reddit is the most cited domain across major AI models such as ChatGPT, Perplexity, and Gemini. Google's AI search results also reference Reddit in about 5.5% of replies, indicating increased visibility and integration of Reddit content in AI-driven search. This development reflects a shift in the AI and internet search landscape, with Reddit outperforming traditional sources like Wikipedia, YouTube, and Google itself in terms of citation frequency. Industry observers note that this trend is reshaping the competitive dynamics of the search business amid the growing influence of AI.