Minisite Education
It took a long time before I could put into words why I found writing mini sites so enjoyable. I am an introvert. I like people, but I also treasure time alone thinking about things I find interesting, reading, and writing.
I do not like sales. I have read books on how to do sales and can't imagine myself cold calling customers, attending networking meetings and dealing with rejection. One of the most wonderful things about having my kids grow up was that I no longer had to participate in fund raisers!
At some point I realized that with my mini sites running AdSense or Ebay ads my only requirement was to write pages other people found interesting. If my sites attracted traffic, they would look at the ads sold by Google or Ebay, and click on them. If I could build enough interest and attract enough visitors that would pay me an income. It works!! Google wires the money directly to my bank account every month.
It is a really strange way to make money, that is hard for parents, spouses, and friends to understand, but it works. I have no customers, I don't need an office, my income continues even when I take the day off and while I sleep. I can spend all the time I want reading, studying and learning about whatever subject(s) attract my interest.
Of course you have to remember that the reading & studying doesn't count unless you do the writing. The pages have to get published before they can benefit you.