From the 2009 PayPal Developer's Conference (http://ebay.com/devcon/).
Driving Business with PayPal
Many SMB customers are looking for a higher level of integration out of their ecommerce system to drive stronger end customer relationships. Some of the more common additional pieces of functionality above standard checkout processing includes marketing campaigns connected into their product purchasing (special promos, discount coupons, etc.), tie-ins of transactional information into their online administration, and the acceptance of online invoice payments tied into their financial system. In this session we will look at taking PayPal integration to the next level through technologies such as Payments Pro, Instant Payment Notification, and Recurring Payment. In the process not only will we look at lessons learned and recommendations based on the experience of developing several of these end solutions for small and medium businesses. We will use live site case studies but also walk through the design and code of examples.