The Devolution of Mickey Mouse
View this link:
http://www.guardian.co.uk/film/gallery/2008/nov/13/mickey-mouse-walt-disney-at-80?picture=339648766
Here is a fantastic Guardian slideshow with commentary by Neal Gabler on the creation and devolution of Mickey Mouse, marking the 80th year of the character. It makes a great case study in creativity and popularity induced erosion.