My three oldest kids have just returned from their grandparents' house. They run into my office, each child waving a twenty dollar bill. “Look at what we got for helping Oma in the garden!” Their sweaty faces are beaming with pride. “And how will you spend your newfound wealth?” I ask, already knowing the answer. “I’m getting V-Bucks,” 11-year-old Elowen announces. Her twin sister, Linnea, nods emphatically. “It’s Robux for me,” declares 9-year-old Hallden.