Mickey Spillane once said, “The first chapter sells the book; the last chapter sells the next book.” Unfortunately, some authors interpret that truth as meaning they should end a book with a cliffhanger. There are (at least) 3 reasons why cliffhanger endings will make readers mad–and angry readers are less likely to read your next book. But before we get to that: This post is part of the Insecure Writers Support Group (IWSG) blog hop. On the first Wednesday of every month, we IWSG-ers share our doubts, fears, struggles, and triumphs. Our awesome co-hosts this month are  Ronel, Deniz, Pat Garcia, Olga Godim, and Cathrina Constantine. Stop by and leave them some comment love. Each…