For computer manufacturers, the key to their business model relies not on the sale of the hardware piece itself, but on the demand for complementary products and applications. Here, the more applications are available for a hardware, the greater are the incentives for consumers to purchase the system. Likewise, the greater the number of consumers willing to buy the system, the more applications will be available. What we are talking about here is essentially direct network effects or indirect network effects or heterogeneous stand-alone benefits or none of the above or all of the above.