“Superfandom: How Our Obsessions Are Changing What We Buy and Who We Are,” by Zoe Fraade-Blanar and Aaron M. Glazer, 2017, W.W. Norton, $27.95, 336 pages. Collect them all. These three words put a smile on every marketer’s face and fear in every parent’s heart. “Collect them all,” as you may remember, was kid-code for “bug your parents until they buy stuff,” making you the envy of everyone in third grade. Your goal now: to capture that buyer’s obsession at the level you’ll see in “Superfandom” by Zoe Fraade-Blanar and Aaron M. Glazer.