Google Checkout provides another option for digital goods sales using their Digital Delivery API. It does not include support for aggregated payments, which are often useful when selling digital goods due to the fee savings from their typical low sales price. But if you're already working with Google Checkout, as we did earlier in this book, integration with digital delivery is relatively simple.
Google Checkout's Digital Delivery arguably gives us less control over the delivery process, but does so at the benefit of simplifying development. Checkout takes care of just about all aspects of the purchase, from initiating payment to notifying the buyer with download instructions.
Digital Delivery for Checkout includes three delivery methods:
E-mail
Key/URL
Description based
E-mail is the least recommended and most manual method. The customer will receive a confirmation page after submitting their payment. This page will let them know they should receive instructions...