Will you sell items on the other auction sites except ebay?

There are a lot of things going for eBay.

Safety (even though people like to cite the problems it had in the 1990's as reasons it's not 'safe)

Traffic

Longevity

Branding

Robust back-end systems.

They have all this as well as a great 'concept'. One big complaint people had was their horrible, horrible fee structure, but they just announced their simplifying this and LOWERING their fees.

So, in order to compete against them you're going to need another angle to convince people you're better than eBay in these (or another) area.

Bonanza.com is a website whose angle is 'we have flat fees and eBay sucks'. They do 'okay', and I have actually listed and sold items on their site before.

Their BIG flaw is that you have to log into their site periodically in order for your items to sell, instead of having your items' performance be based on the performance of the listing themselves. This hurts them - when sellers see their items SELL they will return - it shouldn't be based on how often they log into their account.

Just remember, you have to promote a STRONG difference - since you're not the only competitor to eBay that has come along.