The emergence of generative artificial intelligence is transforming the marketing landscape. Tools like ChatGPT and Midjourney allow brands to create ads, catalogs, and social media posts in seconds, tasks that previously required teams of photographers, designers, and copywriters. This technology not only reduces costs and time but also opens the door to unprecedented personalization: in theory, each user could receive a version of the product or service tailored to their preferences. However, this advancement poses a significant challenge: authenticity. More and more consumers are questioning whether they can trust what they see. An example of this was the controversy surrounding Amnesty International in 2023, criticized for using AI-generated images to illustrate protests in Colombia. Although the intention was to protect the protesters, many perceived the campaign as manipulative. The use of AI-generated images has spread in sectors like hospitality and tourism, where hotels and agencies use them to showcase destinations and experiences. To analyze how customers react to these images, two complementary studies were conducted. In the first study, 338 participants evaluated hospitality scenarios presented with either real or AI-generated images (properly identified). The scenarios varied based on the type of service (hedonic, pleasure-oriented, or utilitarian, focused on functionality) and the level of involvement in the purchase decision (high or low). The second study, qualitative in nature, gathered impressions from 60 participants about their reactions to these scenarios, allowing for a deeper understanding of the reasons behind their trust or distrust. The results are clear: real images generate a higher intention to use and recommend the service. Companies using AI images are perceived as less professional, impersonal, or even misleading. Many participants noted that these images make it difficult to imagine the authentic experience. The rejection of AI-generated images is particularly strong in hedonic services and high-involvement decisions, where experience and emotion are key. In utilitarian or low-importance services, such as fast food, the difference between real and synthetic images is less relevant. These findings can be explained through the processing fluency theory: people trust what is easy to understand and familiar. Real images, consistent with prior experience, are processed more easily and generate trust. AI-generated images, while visually appealing, can evoke a sense of unreality that negatively affects the perception of the message. The study warns companies: while AI can be an efficient tool, authenticity remains a fundamental value for consumers, especially in services where experience and emotion are decisive. Synthetic images may be useful in functional and low-involvement contexts, but they should always be used transparently, clearly informing the customer when an image has been artificially generated. In conclusion, the key is to find a balance: AI should be a creative ally, not a substitute for the human touch. Brands that manage to combine technology and honesty will be the ones to maintain their customers' trust in an increasingly digital environment.