With over 100 million users, PayPal has more accounts than Discover and American Express combined. PayPal offers a wide range of payment technologies, but it’s not always clear which is the best choice for a website. This book, the first to cover the PayPal SDK, is written by a PayPal employee with great knowledge of the technology. It gets under the hood to show how the different technologies work, how to choose the right solution, and how to implement it - complete with real-world examples. The book shows developers how to integrate PayPal directly into websites to make use of its payment technologies. This allows developers, no matter what language they program in, to build shopping carts or similar channel products with PayPal as a payment option. Merchants can also use this book to find out the basics of e-commerce, where PayPal fits in, and how they could take a DIY approach to solving their e-commerce needs.