I had luck with this picture; it was placed on the front page on Shutterstock when I uploaded it a year ago. This gave it so many downloads that it got a favorable search placement, that it has kept since. In one year it has earned me $35, from 100 downloads.
It sells reasonably well on several of the other microstock sites too, but nowhere near as well as on Shutterstock.
© Photographer: Gaja | Agency: Dreamstime.com