This has always puzzled me. Some cost substantially more and others substantially less. Within one to two years those not offering online courses will be the exception. On your site, you list listserves and newsgroups. Other than a desire and drive to learn I would say not.
Students range from teenagers, single moms and seniors to doctors, lawyers and graduate students.
Though the universities themselves that are offering these online courses are very credible institutions, there is still a stigma of inferiority about an online degree versus the degree achieved in the traditional way. Standardizing accreditation procedures certainly would help. Time, I believe is the key. As the numbers of online students and credible institutions providing online options continue to grow, I believe acceptance will take care of it self in its own good time. Combining the development of high speed Internet access, the convenience of on-demand training and lower costs, I foresee this type of education becoming an everyday occurrence in our lives.