Replying to Sell photos online for free?

does anyone have any experience using a free website to sell their own photos and make a little money. I know some of these site exist, i'm just wondering if anyone has a personal preference or knows one with the best "rate" for the photographer. I would really like a free site, because i have never sold pictures, and i only do a little photography. A few of my parents friends just wanted to know if i could sell online, because them and their friends want to buy some pictures