Why consider on-line assessment?

In 2007 I attended a seminar on e-assessment by Professor Geoffrey Crisp, read his excellent book "e-Assessment Handbook" and in early 2008 a workshop on e-assessment. I now routinely use e-assessment, having given up on written examinations. However, I still use a relatively conventional adaptation of assignments and tutorial participation, simply replacing the paper assignments and face to face tutorials with online equivalents. Perhaps it is time to go back and ask: "Why consider on-line assessment?". This and other questions are asked in "On-line assessment" (2002) from the "Assessing Learning in Australian Universities", at the Centre for Students of Higher Education at University of Melbourne.