Books can be shared in study groups, lent between students, checked out from a campus library, bought and sold between terms, and photocopied. Much the same cou

Books can be shared in study groups, lent between students, checked out from a campus library, bought and sold between terms, and photocopied. Much the same could be done for a DRM-free PDF. The only way to complete MyMathLab homework is to pay out for a poorly-written Flash app.