Adrian Slywotzky believes the Internet will overturn the inefficient push model of supplier-customer interaction. He predicts that in all sorts of ma… - Clayton Christensen

[Descriptive research provides] an accurate description or picture of the status or characteristics of a situation or phenomenon.

During the early stages of an industry, when the functionality and reliability of a product isn't yet adequate to meet customer's needs, a proprietary solution is almost always the right solution -- because it allows you to knit all the pieces together in an optimized way.
But once the technology matures and becomes good enough, industry standards emerge. That leads to the standardization of interfaces, which lets companies specialize on pieces of the overall system, and the product becomes modular. At that point, the competitive advantage of the early leader dissipates, and the ability to make money migrates to whoever controls the performance-defining subsystem.
In the modular PC world, that meant Microsoft and Intel (NASDAQ:INTC), and the same thing will happen in the iPod world as well. Apple may think the proprietary iPod is their competitive advantage, but it's temporary. In the future, what will matter will be the software inside that lets users find exactly the kind of music they want to listen to, when and where they want to, with minimal effort.

[There is a distinguishes between] low-end disruption which targets customers who do not need the full performance valued by customers at the high end of the market and "new-market disruption" that targets customers that could previously not be served profitably by the incumbent.