You may be saying "ebay already has free insertion fees." That in part is true, if you list your item for $0.99 or less it was free to be listed. But now you can list your items for free with any starting cost, up to 100 a month. This promotion goes until January 7, 2011.
There are a whole bunch of logistics to it so I have included the link below and the 'most important' fine print for your reading.
Some of the legalities:
Starting September 28, 2010, list your items for free—no Insertion Fees, regardless of the start price of your item. Just list them Auction-style with no reserve price. This promotion has a cap of 100 listing per month and applies to sellers who do not have an eBay Stores subscription.
If you have already sold more than ten (10) items on eBay, your detailed seller ratings (DSRs) must be 4.5 or higher on all four criteria (Communication, Shipping Cost, Shipping Time, and Item as Described) to be eligible for this Promotional Rate. DSR rating criteria for this promotion will be based on the previous 12 months. If buyers have left you DSRs on 10 or more transactions, you'll have access to a Seller Dashboard within My eBay where you can see your current rating. For more information on DSRs, visit the Seller Information Center.
New sellers who don't yet have DSR ratings are also eligible.
That basically says how you qualify for it. For extra details if you are having trouble see the link above. We decided to post this cause insertion fees for items over $0.99 range from $0.25 to $2 so you can save quite a bit in the long run if you sell on ebay.