Nothing you see has any meaning, save for what you give it. A cup, for example, does not contain some inherent "cupness" that defines it. We remember filling it with orange juice in the morning. We remember drinking from it while we read the paper. We remember holding it in our hands, washing it. If you take what we call a cup and break it into its component parts, and break those parts into their parts, you will not find a molecule that is pure "cup." It follows then, there is no inherent "cupness" that defines the shape. We see our past experiences, and so we pour meaning into possessions, often making them desirable.
Millions of people have discovered a new way to fuel desire, turning their attention to the most intangible objects in the world. Virtual items. Zeros and Ones. Things that cannot hide their lack of inherent existence behind our usual senses like touch or smell. We know that the sword with the impressive strength modifier doesn't exist in any meaningful way, but we buy into the fantasy with the most precious currency we have: our time.