It depends on what brands you are selling. Young adult higher-end brands sell on Ebay. Think Anthropologie, high-end denim, Vince, Theory, Trina Turk and such. Designer stuff if it's not too old also sells. Always check out prices if possible to see if it sells and for how much.
Middle- to low-end brands do not sell too well. As poopsie has mentioned, the market is seriously oversaturated.
p-WA