I found the Peter and Donnelly marketing book rather anemic, especially as an assigned textbook for marketing majors in an MBA program. (It was assigned in two of my MBA classes.) At just under 300 pages, it provided only a high-level overview of marketing, and in some cases, the information was stale and outdated. The illustrations and charts are also rather crude and unsophisticated and sometimes downright difficult to interpret.
The only good thing was that it was quick and easy to read, but I didn't really absorb much new knowledge. As a supplement to a curriculum that uses case studies extensively (which is the recommended usage of the book), it is adequate. Each chapter concludes with a section listing Additional Readings, which are probably necessary if you want to really increase your knowledge of the subject.