but who offers these additional services and how are they related to products? Are they conceived of and designed by the same people, or do third parties offer them? How well do products integrate with related services? These questions are fundamental to the changing de inition of products and directly relate to the quality of experiences people have when using them. It is this focus on experience that marks another change in how products are defined and designed. If the combinatorial use of products and services is unsatisfactory the distinctions between them do not matter; to design for a good experience the focus must be on the seamless integration of the two.
When products and services are intertwined in a symbiotic way they become one in use. A good example of this is the Apple iPod music player and the iTunes software and music store. This is a product/service system integrating three separate components: hardware, software, and the web. Each component combines a consistent design language with a tight coupling of capabilities. The iPod for example is designed as only a music player, and relies on the iTunes software for all playlist management and configuration. This simpli ies the interface and moves the more complicated functions to an environment where they can be more easily handled. In turn, iTunes is closely integrated with the online music store, seamlessly allowing people to purchase music and transfer it to their iPod. Products of any signi icant complexity are made up of many components and thus can always be thought of as a system, an interconnected set of parts that work together to form a whole. A product/service system is really just a higher order product with the component parts being wholly formed products and services. In the same way that people may not consider the components of a product while using it, people may not differentiate between the various parts of a product/service system. It is the interactions that people have with the system, the holistic experience of use, that end up becoming the product. Designers are still