Auctions Tips and Tricks
Okay, first to be honest - I've never had much luck with auctions. I'm prone to low-key listings, and I'm lazy. Auctions seem like a lot of work to me. So I never list much, never get my feedback ratings way up there, and consequently don't generate a lot of bidder interest. If you want to be successful, don't do what I do. That's my big tip for you.
Now that I've been so negative and gotten you all excited about the prospect... Plenty of booksellers do all or most of their online selling through the auctions, and do very well at it. You will sell a higher percentage of your listed items in auction than you will on a database. But in general you'll make a little less per item. Except for those oddball items that end up in the centre of bidding war. You'll like those...
Sales Venues
eBay.com The biggest auction site, rumoured to have more than 90% of the online auction market. While it generates more traffic than any other site, it's also so big that your listings can sometimes get lost in the shuffle.
Popula Very hip little auction which specializes in the collectible and the weird.
Books by Bid Specializes in books & ephemera.
Buying
Auctions can be an excellent place to buy inventory. Sometimes a seller will misspell a word in the title, or place an item in an inappropriate category. If you're lucky, the item will bring substantially less than it ought to.