It looks like a new (but more complex) setup for a webmaster, that simplifies the payment and delivery system for the customer. According to the
FAQ page (you may need to sign in to view it), you need to be conversant with APIs to set up their Digital Goods solution. I didn't see any details on where the files are stored and accessed by the paying consumer.
Another product digital goods providers opt for is
Website Payments Standard because it requires less technical expertise and no programming skills. This is what I use, in conjunction with third-party digital goods delivery software. The digital files are stored on your website, not PayPal, with the Website Payments Standard system.