VISIBILITY You want colleagues without access to expensive journals to be able to find and read your work without having to pay exorbitant access fees.
PUBLIC INTEREST Your research is of potential public interest and you want to make sure it can be found and read.
REUSABILITY You want to make your educational materials, research, or data available for reuse and remixing by others.
COMPLIANCE Your funder requires that you make your research and/or data publicly available.
INNOVATION Your work is too interdisciplinary or too innovative to fit in any of the traditional journals in your field.
ETHICS You object to the enormous profit margins of the big publishers (35%).
INCREASED CITATION COUNTS Studies have shown that publicly available work is cited more widely and more often.