Mobile phones used to be a separate market but the boundaries between them and music players are beginning to blur.
The content providers were the money side which paid Real for their streaming software.
Microsoft launched an envelopment attack on Real by providing the streaming server software clubbed with their Windows NT operating system.
A network market consists of several players operating in various adjacent layers.
Such is the case with mobile phones and video game devices which were used for distinct purposes but the digital platforms available today have converged all such usages into one.