When time runs out, the last bidder wins the product and savings are typically higher than 95% off of store retail value...plus No reserves on all auctions!!
As a potential seller, why would I offer my stuff for up to a 95% loss?
Because you aren't taking into account bidding fees...
Lets say you post a bitcoin (approx $3) and charge 10 credits ($0.10), /bid, if final auction price is $0.50 you would receive the $0.50 from the winning bidder, who gets a great deal on a bitcoin, and you receives the $5 in credits from the 50 bids that were place on the item for a total of $5.50. Even though the winner gets huge saving, you come out ahead as well.
That's not a guarantee, your bitcoin could sell for only $0.02 in which case the winner gets an even better deal and you would only earn 22 cents; there's a risk on both sides because if you aren't the winning bidder you lose all your credits. There's no clear advantage on either side and it becomes a strategic game.
I always recommend new posters, to start out with something small that you don't need (good ebook or old cell phone) to get a feel for how it works.