A blue knife in Counter-Strike can sell for $1.5 million. A skin in Fortnite generates more revenue than a blockbuster movie. Tech writer Eric Chan explores the bizarre, booming world of virtual cosmetics in "Digital Couture."Chan argues that skins are not just "pixels"; they are the primary way we express identity in the digital spaces where we spend our lives. He traces the history from "Horse Armor" in Oblivion to the complex skin-gambling markets of today.The book analyzes the psychology of scarcity and the "flex." Why do players pay for items that give no competitive advantage? Chan...