There are thousands of digital items that exist that look the same but are owned by different players and have different ownership histories. A certain item might have been owned by a world champion, giving it extra value similar to an autographed home run ball in the world series. Without some kind of digital signature, it would be impossible to know which exact item belongs to a famous gamer unless you asked the game developer directly to verify its authenticity.
…g that powers Google and Amazon. And Amazon’s targeting is probably more powerful in the long-term. At the end of the day, you telling an advertiser what you are looking for is still a hell of a lot more accurate than the best artificially intelligent guess.