Recently, I've been focused on improving customer experiences for a software company. Clued In, by Lewis Carbone, is the best book I've read about creating customer experiences. And he brings together the concepts of flexible software and marketing. Without an adaptive enterprise it's difficult to create amazing customer experiences because:
Flexible software => Positive Customer Experiences => Customer Loyalty
Of course, a company could still create crazy customer experiences even with quality software. But if your product is software, it's almost impossible to produce amazing experiences with inferior software.
Mr. Carbone offers several articles at his website.