It doesn't seem to say on the package or the paper where exactly it gets put but it does mention itunes and according to the digitalcopyplus,com website you can choose one provider from a list of various providers. I'll copy and paste the info from their website.
Digital Providers will vary for some Digital Copy titles. iTunes, for example, will not be available on all titles. You can, however, still enjoy your Digital Copy on your iPhone, iPad, or iPod Touch through the VUDU or the Amazon Instant Video app in the U.S. Both apps are available through the iTunes App Store and are free to download.