Payment buttons are the means by which you can connect PayPal to your site and start collecting payments for your products in minutes. If you expect customers to come along and purchase only single products from your site, single payment buttons (discussed in Chapter 4) are perfectly adequate.
As your online business grows, however, your product offering will begin to increase and diversify and you'll have to start thinking about ways to increase sales. A good place to start is with some sort of system to allow customers to purchase more than one product at a time, a system commonly known as a shopping cart.
PayPal provides a complete Shopping Cart system, built with the same PayPal buttons you've come to know and love. All you need to do to get started is place Add to Cart and View Cart buttons on your product pages [Hack #45], and PayPal does the rest.
The hacks in this chapter help you manage your online inventory, fulfill orders, customize your customers' experience, promote your online store, and sell more products with the PayPal Shopping Cart system.