Cold-Start Problem
The difficulty of generating relevant recommendations when a system has little or no prior user interaction data. A new ecommerce site with no purchase history cannot rely on collaborative filtering ("people who bought this also bought that") because there is no collective behavior to analyze. The solution is a rich catalogue of structured product attributes. Attribute-based filtering can produce precise recommendations from the moment a product is listed, because it matches items by their inherent properties rather than by user behavior patterns. The cold-start problem affects not just new businesses but also new products, new categories, and new users within an established platform.
Example: A small coffee roaster launching its first website can recommend beans with similar flavor profiles by tagging each product with origin, processing method, and tasting notes.