A new study by Katana, which tracked 375 product brands across sales channels like Shopify and Amazon, found that stockouts (especially for bestsellers) result in losses far exceeding many companies' expectations. The study indicates that a typical brand loses approximately $21,000 annually due to bestseller stockouts, with the top 25% of brands losing around $82,900 per year, and the most severely affected 10% of brands losing over $268,000. The report warns that this cost will further increase as shopping behavior shifts towards AI assistants, because when AI tools recommend products, shoppers won't even see an option if a product is shown as out of stock, leading them directly to competitors.