My Linux server tutorial course site http://GREP101.com brings in $700 on a good month and $100 on a bad one. Simply a reflection of the fact that I don't have the necessary things in place to drive consistant traffic to the site - when traffic comes then I get good conversion and a full course, but if not, not.
I keep it going mainly because the feedback is very encouraging, (people really do get a buzz out of learning this stuff!). It requires only a small bit of work each week to keep ticking over, but honestly it doesn't make enough to justify that if money was the only issue.
Nice site, I work as a Systems and Network Engineer and have been wanting to do something like this for some time. I've had similar things for PHP before that got great feedback but I did it for free.
My main worry is how much content I produce and how to value it. Do you ever get requests for refunds? Have you had anyone unhappy with the course etc? Have you done any marketing at all? Or have you just dropped your link in a few places?
I keep it going mainly because the feedback is very encouraging, (people really do get a buzz out of learning this stuff!). It requires only a small bit of work each week to keep ticking over, but honestly it doesn't make enough to justify that if money was the only issue.