Most Lego fans often have some excess parts, sets, or minifigs that they would like to make an extra buck on. Of course you can try to sell your wares right here on CC, but this is often unfeasible for non Castle themed items. The next logical option, then, is to sell your Lego on third party websites. When first looking for a place to sell, the choices can be a bit overwhelming. Most people find that eBay and Bricklink are the easiest and most risk free sights to sell on, but which is better? Here is a comparison based on my experience as a seller on these sites (the table is a bit small; hold the control key and scroll up to zoom in).
In conclusion, eBay is usually better for selling unsorted lots of combined minifigures, sets and parts. Bricklink is usually better for selling individual Parts, Minifigures, or Sets.