A former student writes an essay on what Kurt Vonnegut was like as a teacher at the Writers' Workshop:
He told us in workshop classes, “You’re in the entertainment business.” He impressed this upon us over and over again. Therefore, he said, “Your first job is to hook the reader. Your second is to keep your reader reading.”
Curiosity about the smallest thing could keep the reader engaged, he said. He cited a story he'd read in which the main character has a worrisome loose tooth. The suspense of what was going to happen to that tooth was enough to keep him turning pages.
He admitted Cat’s Cradle was designed by this principle. The chapters were structured as jokes. They were brief. They were intended to sustain even the shortest attention span.