> I never understood why eBay set things up to enable sniping.

I've seen studies on auction method that suggest the difference in the final price (between explicit end time and the more traditional extend-until-bidding-stops method) is negligible for online auctions except in a few special cases. This is a marked difference from the expectation that, like a real-world in-person auction, the extending deadline might encourage further spur-of-the-moment bidding.

Whether it makes much difference to the final price or not is immaterial though if the buyers believe that it does. This is one of the (several) reasons why eBay won out against similar competition in the early days: buyers felt they were getting a better deal by being able to snipe so favoured eBay with more of their attention and this brought more sellers to the platform (which attracted more buyers, and so on round the loop). It is telling that to deal with the extra load imposed on the system by external bots refreshing pages and putting in automated bids, instead of switching to an extending auction model they implemented what is almost a built-in sniping feature.

Auction sites have to be very careful (or just very lucky) in their messaging, to convince both sellers and buyers that they are getting a good deal - any major change to how eBay works could upset the balance that they currently have in that regard and start a flood in the other direction (the more people leave, the more other people will think about leaving) to the building toward critical mass that was how they won out in those early days.

In my experience, most purely online auctions, other than eBay, do work that way. Numerous auction houses, for example, including essentially all the major ones, have their auctions online now: when they are hybrid, that involves online live bidding where an online bid will cause the auctioneer in the room to keep the lot open for more bids; when they are "timed" or "online only", times are extended in some way on bids near the deadline. It does, in fact, work much better. There is still an advantage to bidding very late: there is no disadvantage, and it lowers bids in cases of irrational or imperfect opposing bidders. But it limits that process to something that can be done by hand.

eBay really seems to be the only auctioneer using the snipable process it uses.

This is how the popular car auction site bringatrailer.com bidding process works for cars sold on their site too, a quirk of which is that it makes watching the end of the auctions live online kinda fun, especially given the discussions that break out in comment section on each car up for sale while folks nervously watch the current candidate for the final bid cool down.

Much like your example, in the two minutes before the end of the auction, every new bid placed extends the auction clock by another two minutes, the winner hasn't won the auction until two minutes have passed with no further counter bids.

> https://bringatrailer.com/how-bat-works/

Completely agree with this. It's very odd that the eBay algorithm has a hard stop, as it directly discourages the price from rising when the bidding is hottest, and is absolutely susceptible to sniping.

AFAIK eBay does do this but I’m not sure if it’s only certain categories or it’s configurable by seller. I’ve definitely seen it happen

That's how whatnot does it as well (what eBay badly copied as eBay live)

This how Trade Me (NZ auction site) works: any bid in the last 2 minutes delays the close time to 2 minutes after the bid. That can happen repeatedly, and I've seen it go on for over 20 minutes on highly contended auctions. It works well.

This is how Yahoo! Japan Auctions works. If an auction receives a bid in the last few minutes, it is automatically extended.

It works quite well!

Guessing here - but they are probably relying on game theory / auction theory. They have a built in "sniping bot" - by allowing you to type your highest price, and it will auto-bid for you until that price.

The fear of being sniped encourages you to bid your maximum value, and not just wait and see if you can sneak in a lower bid. This is what all auction sites want.

Another eBay precursor auction side, onsale.com, had the same setup. The auction ended at X date/time or five or ten minutes (I forget which) after the last bid was made.

There is no need for that. They only need to implement a closing auction like stock markets. But eBay hasn't done anything since the 1990's except raise fees.

This was my belief for many years, but then I tried sniping (with the same prices I was putting as my maximum bid before!) and my success rate skyrocketed and the prices I was paying dropped.

It seems that despite repeated reminders and explanations, there are three groups of people using eBay "incorrectly" that make the sniping strategy viable: 1) People who do not understand proxy bidding and think that they "need" to repeatedly bid in increments. 2) People who are irrational about their price ceiling and are willing to bid above their price ceiling because they want to "win". 3) People who want to drive up the price either to deprive others of a good deal, or to drive up the price on behalf of the seller by starting a bidding war with the two above groups.

From a sellers perspective it is common to deal with buyers who won't pay because they paid "more than they wanted", although this is against the eBay ToS and a bid is a contract to purchase the item, because there are few consequences for not doing so.

For some reason, auctions with more bidders seem to attract more bidders, whereas auctions with zero bids seem to go unnoticed. I wonder if this has to do with eBay's search ranking algorithm or some other irrational behavior that I don't understand. At any rate, bidding with 5 or less seconds left to go seems to defeat the above behaviors. I find it distasteful and irrational but it works so I put up with it.

eBay's reputation and trust network is really what makes it a viable product at this point. Given how unreliable Facebook Marketplace buyers are and how many scams are present, I would hesitate to conduct any major transactions beyond a local area.

Snipers essentially convert the ascending-bid proxy auction used in eBay into a Vickrey second-price sealed bid auction, allowing a buyer to not reveal their preferences to other participants. In theory, with rational participants, this shouldn't have any effect on revenue. In practice, buyers do not always understand auction mechanics and delay setting the highest price they're willing to pay until they are outbid. If they're outbid 3 seconds before the deadline, they lost.

Establishing the price ceiling is difficult, though. You might arbitrarily set it as $23, but be sniped at $23.30. The sniper bot only needs to bid that small increment over your arbitrary ceiling.

Can you really say that $23 was your hard limit, or would you have paid $23.40? Unless you're buying something also available at retail, nobody can be that accurate in foresight.

Sniping removes the 'contemplation window' to reconsider your bid.

The act of bidding itself shows interest and raises the price.

From what I understand, the reasoning behind the snipe method of bidding is to avoid showing to other bidders that there is interest, leading to the, supposed, outcome of more likely being the only bidder and thereby receiving the item at the sellers starting bid price (or slightly above) rather than at the "max one was willing to pay" price.

Sniping is the only way to bid for two reasons:

- bidding more than once and allowing time for others to counter bid drives up the price through competition for the item. Sniping also removes the temptation to counter bid, rather than to stick to your maximum bid.

- not sniping allows the seller to do ghost bidding, letting them discover your maximum price (including counter bidding). Here someone always out bid you (the ghost bidder) but the seller says the winner didn't complete the sale so offers it to you at your highest bid.

I have lost most of my bids to bots. Bots will literally bit at hh:59:59. The ceiling value doesn't work unless you bid way above the asking price.

Auto bid isn't the same as sniping. Sniping hides information about demand. Auto bid can't hide information as soon as there is another bidder.

This is most likely the reason. I could see a lot of "buy for me bot" users deciding that they really did not mean that color shirt (or some other reason) when they asked it to buy a "brand X shirt in size Y" and forgot to tell the bot what colors they would accept as options and did not realize the bot might buy an "electric purple" (or some other color they dislike) shirt because it was not constrained in color choice.

And I prefer to use sniping bots because they let me revise my bid all the way up until the auction ends. If I put a bid on something and then sleep on it and decide I don’t actually want to pay that much, I can lower my bid or cancel it. If I bid with eBay directly then I loose that flexibility. It has nothing to do with trying to outsmart people or be sneaky.

I run up the prices in less competitive auctions just for fun occasionally, especially if I think someone is getting too good a deal.

why would you bid the highest price you can afford in an auction? the seller agreed to auction the thing; they could have just offered it for a set price.