This is a serious power user’s book. The author is a PayPal employee, managing the development program at the company, so this is essentially an insider’s look at how to make your external commerce site interface effectively with the PayPal system for commerce payments. Williams knows how PayPal works; he’s helping to build it.

At first glance, a book about PayPal by a manager from PayPal might seem self-serving, but the value of the publication lies in the intimate knowledge demonstrated and the fulsome detail about how to develop for PayPal functionality. Essentially, this is a case of the PayPal programming manager telling you how to interface with his application seamlessly.

The topical coverage is quite technical, with plenty of code examples, and spans issues covering the application programming interface, transaction processing and clearing, report generation, security and encryption, and troubleshooting. This is not a casual book; consumer market PayPal users or small business operators could easily find it well beyond their capabilities. Information systems academics will find it interesting, but computer science colleagues will likely have more use for it as a scholarly reference, owing to the high degree of technical detail.

This is PayPal for the serious user and should prove to be a very valuable desk reference for the active commerce site developer who is engaged with retailers that have selected the PayPal payment channel for their business.