Yes, I am not in its demographic, but it was fascinating to learn about how the world of gaming has developed a whole economic model in the form of "XP" or "Experience Points". Different worlds use different terms but generically, these are points earned within the game and then spent on game artifacts or items or abilities.
Things get interesting when players decide to cross over between the gaming world and the 'real' world and use real money to buy or trade artifacts.
Here's a fascinating and amusing article on that very topic:
"IF YOU HAVEN'T MISSPENT HOURS battling an Arctic Ogre Lord near an Ice Dungeon or been equally profligate spending time reading the published works of the Internal Revenue Service, you probably haven't wondered whether the United States government will someday tax your virtual winnings from games played over the Internet. The real question is, Why hasn't it happened already? " (from "Dragon Slayers or Tax Evaders?")