Tom Fishburne is a greaaaat cartoonist that publish on his own blog his ideas about business through cartoons. Mainly about retail, brand management and marketing, his cartoons are not only funny but also very meaningful about new trends and retail strategy. He began drawing cartoons on the back of his Harvard Business School cases. Some may be as valuable as the cases as Fishburne as a sharp and clever view on marketing stuff.
See especially his video : Everything I needed to know about innovation, I learned by drawing cartoons :