By embedding information technologies into tangible products a new class of products is created that we call smart products. Smart products use product information in product-centered communication with users. Communication of smart products is handled by dynamic product interfaces. We present a model for QA-based dynamic product interfaces and its implementation DyPI. It is based on a schema-driven question-and-answer approach for Natural Language understanding and generation. Product information is described by web-based semantic representation formats that are stored in distributed repositories. Communication between smart products and users are run on a dedicated middleware (Tip ‘n Tell) that supports user interactions with products by wireless, RFID-based infrastructures and manages requests on product information.