This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
To expand, "D" for "Define", so "-Dname=value" constructs a name/value pair and catalogs the name in the JVM's System Properties collection. This collection is convenient as a quick-and-dirty command-line option facility (since you don't have to parse it yourself), as the place to set environment features of the JVM itself, and as a way to support options to "add-in" systems which the application doesn't need to configure itself. Things like logging options, for example.
Customer surveys are for companies who didn't pay proper attention to begin with.