Should teachers sell their lesson plans online?

A recent New York Times article reported on the “thousands of teachers” selling their lesson plans online and whether or not it is appropriate for them to do so. According to the article, teachers are selling lesson plans online on sites like Teachers Pay Teachers and We Are Teachers, but more districts are beginning to question whether they should be allowed to do this. Some teachers say they use the money to buy classroom supplies, and others use the funds for personal expenses. Joseph McDonald, a professor at the Steinhardt School of Culture, Education and Human Development at New York University, told the Times that the online selling cheapens what teachers do and undermines efforts to build sites where educators freely exchange ideas and lesson plans.
One New York educator, Lisa Michalek, reportedly has earned $31,000 from selling lessons, like an earth science curriculum that sells for $59.95. Another New York educator who has purchased PowerPoint Presentations from Michalek said she hates “reinventing the wheel” and starting with Michalek’s presentations saves her hours each time.