earning a little extra income

The only content site I've ever used is Constant Content.

I did (do) well there. They edit with a fine tooth comb and encourage you to sell your pieces for reasonable rates.

I go through phases where I will add stuff and then not for a while. I prefer magazine writing, but find it good to bring in a little extra money.

Sometimes you just need to try and find what personally works for you.
I know some people have great success with some sites, while others don't.

I agree with Arisa here, you will need to try and find what works for you.