This document discusses the arguments for being open with educational content and resources. It outlines 8 reasons to be open: 1) Education is sharing, 2) Buy one, get one (political argument about public funding of research), 3) The paradox of free (financial argument that free resources don't hurt sales), 4) The $5 textbook (financial sustainability of low-cost open textbooks), 5) Facilitate the unexpected (openness enables new ideas), 6) Continuous improvement (openness allows improving resources over time), 7) Content is infrastructure (open content fuels innovation), 8) Do the right thing (openness fulfills our moral responsibility). The document provides examples and evidence supporting each argument.