Give people nice packaging, labels, manuals and posters etc. and it adds real physical value. People understand they should pay for physical things and like to keep them. Bizarrely, the most costly part to produce, the software, has no real perceived value because it is not physical and costs nothing to copy. However illogical, some people feel a bit cheated if they have no free download and will be loath to pay just to play it. If there is a free download and they like it, they may well want to buy a nice package version. It works well and leads to no bad feeling.