Class occurs when the student logs on to the computer at his or her convenience. The class will be there when the student is ready. That's a wonderful advantage to those with full time jobs, full time families, transportation problems, special needs or interests. One must log on and be prepared to read through many pages and comments. They have definite start and stop dates, many with assignments due weekly.
Technology can be unreliable.
The plan to submit homework at the last moment can be defeated with a busy or down server. You should always have a copy saved to a disk or a hard copy so you can resubmit. Failure to have a copy leads to more work. Students report spending approximately 7-9 hours per week on a typical online course. There are other forms of course delivery that may be more appropriate.