ProductCart allows you to flexibly handle the sale of electronically delivered products. We refer to these products as Downloadable Products or Digital Products.
What is common among all downloadable products is that a download link must be delivered to the customer once an order has been processed. Many times, a license or unlock key must be provided as well, together with product-specific download or installation instructions.
ProductCart is built to handle all of this very efficiently. The Downloadable Products features in our shopping cart software were created specifically for the electronic delivery of digital goods such as downloadable software, electronic documents, eBooks, images, etc... Of course, we sell our own software online using ProductCart!

Publishers of software and other digital products are concerned about delivering the download URL to the customer due to the fact that the link can be easily provided to other, unauthorized users. Companies often protect themselves from the unauthorized download of a digital product by adding barriers to the use of the product after it has been downloaded (e.g. License Key, Serial Number). ProductCart addresses both security concerns (unauthorized download and unauthorized use after the download has taken place).
ProductCart uses server-side file buffering to hold the file in a virtual, temporary location while it is being downloaded. Because the file is not downloaded from its actual location, the location of the file on the Web server is completely hidden. When the download begins, a pop-up window will be shown, which will allow the customer to save the file to their computer. The file name is also shown, but the physical location of the file on the server is not provided.
The download link provided to customers (e.g. through confirmation e-mails, pages containing details about previous orders, etc.) never points to a file. Rather, it contains code that allows ProductCart to locate the file that needs to be downloaded, and check whether or not the customer's eligibility to download the file has expired.
In other words, you can set the download URL provided to a customer to expire after N days (each download link provided to any customer is unique). If a customer clicks on a link that has expired, the file download process is never started. So regardless of whether or not the Hidden URL (hidden download link) feature mentioned above is in use on the store, the file location cannot be determined.
This security measure attempts to limit the damage that a digital product publisher would suffer in scenarios such us a URL being illegally sent to multiple individuals via e-mail or posted on a Web page without authorization. Even if the URL is posted on a Web page without authorization, it would be rendered useless after the N days have passed.
A license containing up to 5 pieces of information can be delivered to the customer with the purchase of a Downloadable Product. Many publishers of digital goods protect the unauthorized use of their products by requiring that the customer enter some type of unique license upon installation (e.g. software) or fruition of the product. Since the type of license needed to unlock/use a digital product varies dramatically from product to product, and from publisher to publisher, the Downloadable Products Module (DPM) within ProductCart was engineered to be as flexible as possible with regard to how license information is generated.
If more than one Downloadable Product is included in an order, a license is separately generated for each item and included in the order confirmation e-mail (e.g. an order for two different software applications). If more than one unit of the same Downloadable Products is included in an order, a license for each unit of the product is generated and included in the order confirmation e-mail (e.g. three licenses of the same software application). More information about how a license is generated.
At Early Impact we strongly believe in being the very first users of most features added to our shopping carts. And support for digital goods is no exception: the digital products features in our shopping carts are used daily on our own, ProductCart-powered software store to sell software online. We use ProductCart to sell ProductCart :-)
In our case, a 4-part license is dynamically created when customers purchase a copy of our shopping cart software. ProductCart connects to an external license generator that creates a license key, a temporary user name and password, and stores the customer's e-mail address with the license. Everything is saved to an external database that powers our licensing system.
Our own experience helped us fine-tune this area of ProductCart through the years: the downloadable products features are flexible, robust, and work great for software companies like Early Impact! A knowledgeable developer will have no problems at all configuring ProductCart to fit all sorts of scenarios.