Software downloads are a key metric for all open source vendors, as well as for proprietary vendors who offer freemium versions of their products. Tracking the volume of software downloads provides management with a good benchmark of anonymous community interest and momentum. Although I'd argue that it's critical to track all downloadable assets (including white papers, webcast archives, various marketing collaterals, etc.), product downloads are an important community signaling device – they indicate an intention on the part of the downloader to commit time to explore, test and use your product.
Website registrations are another key metric of volume engines, indicating what part of the community has transitioned from anonymous to trusted status. Product downloads and website registrations are not perfectly correlated (registrations are usually the result of many factors including non-product downloads, marketing campaigns, website promotions, etc.). That said, presenting downloads and registrations on a single dashboard chart gives management a macro-level understanding of the motion and relationships between these key metrics. Note that, in our example graph, downloads scale to the left vertical axis and registrations scale to the right. Also note that the graph tracks new downloads and activity from repeat downloaders separately, something I strongly recommend.
The Product Downloads and Registrations graph is a top-level dashboard tool. A properly instrumented volume engine allows management to drill into the numbers behind the graph to reveal performance details. The Asset Download Tracker is a handy intermediate-level scorecard that shows download action and performance against targets. The graphic is a screen shot snippet from a model I've developed to help clients understand and implement volume engine concepts. The scorecard is fed from lower layers of the model, which track all asset download details. In turn, data in the scorecard flows upward to the Product Downloads and Registrations graph above.