because it is excellent.

The book is [link|http://www.amazon.com/exec/obidos/ASIN/0066620694/002-5025397-1904017|The Innovator's Dilemma] by Clayton Christensen. The thesis is that there are two basic kinds of innovations. The first is a sustaining innovation, by which he means an innovation which makes a product better at what it already does. He calls this sustaining because existing companies have no problem understanding the value of the innovation and reacting appropriately, no matter how drastically they have to redesign their businesses to do it. The other is a disruptive innovation, and that means an innovation that makes a product which is unable to meet the minimum needs of the existing market but which can be expected to do so in good time. He named them that because they tend to destory existing dominant companies and replace them with new ones.

The reasons why disruptive innovations - even ones where the CEOs of existing companies recognize the risk, consistently destroy companies are complex and fundamental to how businesses work. I would say more about it but the book costs under $10, and I think it is better to read it than listen to a bad summary from me.

Cheers,
Ben