According to the Bureau of Labor Statistics, the average cost of a textbook increased 135% since 2001 through 2016-2017*, and then the average price started to fall due to competition from used book sales, rental programs, and OER**. Used books and rentals still cost money while OER don't cost them anything; as many students pay for textbooks with student loans, the use of OER therefore helps to defray costs for students.
Additionally, the ability to adapt the material gives professors more control over the materials they use in class, letting the textbook fit the course instead of the course fitting around the textbook.
OER have been put into use in schools large and small, public and private. Here you'll find collections of OER by type and source, as well as news about OER initiatives all over the U.S.
SUNY Geneseo's Milne Library has developed the OASIS tool to make finding things easier, and it searches more than 100 sources for OER content.