Single niche v Main niche, but with a sub niche.

I originally based my website around a single niche which is make money affiliate marketing, but I soon decided to also have a kind of sub niche, to give my site a bit of a broarder scope, I believe making money, be it just an extra income or your main income, is qiute closley related to health and wellbeing, after all being broke isn't very good for your health is it, lol.

So, with this in mind, I made affiliate marketing my main topic, but I also have drop down tabs labeled "Healthy" "Unhealthy" "Product reviews", I have spent some time searching google for peoples thoughts on this, and have found that some bloggers go for single niche while some prefer multi-niche, with differing opinions in between etc, but I thought I'd put this question here, just to get peoples thoughts.

Russ