http://www.nytimes.com/2015/09/06/technology/a-sharing-economy-where-teachers-win.html What kind of tunes do you think Iago, the villain in William Shakespeare’s “Othello,” would listen to if he had an iPhone? That is the kind of question that Laura Randazzo, an exuberant English teacher, often dreams up to challenge her students at Amador Valley High School in Pleasanton, Calif. So, when Ms. Randazzo heard about TeachersPayTeachers.com, a virtual marketplace where educators can buy and sell lesson plans, she was curious to find out whether the materials she had created for her own students would appeal to other educators. A couple of years ago, she started posting items, priced at around $1, on the site. Her “Whose Cell Phone Is This?” fictional character work sheet has now sold more than 4,000 copies. “For a buck, a teacher has a really good tool that she can use with any work of literature,” Ms. Randazzo said in a phone interview last week. “Kids love it becaus...