I've narrowed my niches to three or four: stock investing, my life (humor), and writing about disabilities.

I was happy with these niches. Then I discovered that one of my articles, a product review of an item I tested on myself for sciatica relief, went what counts for me as viral--almost 1000 views and over 500 reads in about a month. I want to reproduce results like that.

That tells me the adage is true--people most want to read about something that solves a problem for them. So now, I am planning to change to a new article series focusing just on products that I've used and reviewing them.