This is a term used by online auction website eBay. On this day eBay waives all listing fees for sellers, therefore providing a financial incentive for people to offer more items for sale. A free listing day can be roughly expected once per quarter. The various eBay websites are likely to hold free listing days at different times. Therefore, if sellers are not concerned about the currency in which they list items, it is theoretically possible to utilise up to four English language free listing days every quarter - one from the US, UK, Canadian and Australian operations.
From eBay's point of view a free listing day generates activity on the site, with sometimes hundreds of thousands of new items uploaded. This in turn stimulates bidding activity and thus increases final value fees.
There are two schools of thought on free listing days. Some sellers love them, others hate them.
Those that love them often save large numbers of items specifically for listing on this day. Quite often these items are of a low quality and wouldn't normally justify ordinary fee payment. Those that do sell are just money for old rope from the seller's point of view. However, one of the reasons eBay introduced listing fees to start with was to increase the quality of items on the site, ridding themselves of five cent phonecards for example.
The sellers that hate free listing days find that there is much more competition from other sellers. Although the number of items for auction have dramatically increased, at a single point in time, this has largely had no effect on bidders. Therefore, conversion rates go down and less items sell.
It can also be said that generally on a free listing day the eBay sites are plagued with stability issues. Quite often certain functionality becomes temporarily unavailable due to massively increased load. Occasionally sellers are charged fees by mistake if for example items listed through an application programming interface, or third party auction management tool, have been overlooked for fee refunding. This in turn creates an increased customer support workload as accounts are manually credited.
There can also be a number of free listing day variations. These include penny gallery days and free listing for Buy it Now items. Last year the eBay UK operations had a free listing fortnight for items listed using eBay's electronic payment provider, Billpoint.