Quantity Manager is now available within Selling Manager to US registered sellers. Click here for details.
One of the features of eBay's "Best Match" algorithm is that it takes into account recent sales. For example, when your multi-quantity, fixed-price listing makes sales it is given a boost in search compared to those listings that have had fewer sales. This boost is also carried over to the first relist as long as the original listings isn't changed significantly (title, price, etc). This algorithm along with the current fee structure encourages eBay sellers to place all their inventory within fewer listings.
The problem with this algorithm is that it works contrary to buyer behavior. A buyer may be more likely to purchase an item from a seller if only a few items remain. A seller who lists all their items in one listing often finds themselves with little or no sales compared to one who only lists a fraction of their inventory within the listing.
Quantity Manager automatically handles the quantity of fixed-price listings so they can keep an artificially low quantity visible to buyers without running the risk of selling out of the listing. All the seller has to do is tell Quantity Manager the quantity in stock and the quantity to maintain in their listing. We'll refresh your inventory anytime a buyer makes a purchase until you run out. We free up the seller to do other activities such as improving the buyer experience.