So scraping bots and “buy for me” bots are bad, but the incredibly annoying sniping bots are OK? That sure feels like a double standard.
Many years ago, there was an auction site called uBid. They had the sane rule: Bidding is open as long as there have been bids in the past 5 minutes.
So the end date could be January 24th, 3pm, but if someone bids at 2:58pm, the deadline is extended to 3:05pm. And it keeps going.
You know, like how auctions in the real world work.
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.
Did they measure the impact of people who stopped using the platform due to their bids being sniped?
eBay really seems to be the only auctioneer using the snipable process it uses.
For example, suppose the current price is $1 and the current winner is someone who bid $2 as their maximum bid ceiling. If I bid a $3 maximum, then I become the winner at a price of $2.
In this model, there is no need for snipping and those who honestly declare their maximum ceiling from the start are in no disadvantage compared to those who frequently update their bid, nor do they overpay.
Early bids make you commit to matching other bidders’ exploratory bids. You lose out on the (naive) dream of a “great deal”. Sniping (without paid-for bot assistance) is a costless way of not revealing your ceiling until the last moment (and it commits you to actually sticking to your ceiling because there isn’t time to rebid later).
If everyone bid rationally, this wouldn’t matter, but it’s very easy to convince yourself that you can stomach bidding just a little more than your ceiling just to win the item. This cuts two ways: last-minute bids prevent this behavior from others while also stopping it in yourself.
Not that this is perfect either, often it means you can push other people’s bids up to their max even though you have no intention of buying the item. I’ve seen it as a seller and felt bad for the buyers
I've never quite understood why people get so upset about sniping on eBay. Anybody can snipe. That's just the best play. Any time I want to bid on something on eBay, I just set my max bid on the sniping tool instead of on eBay, and then forget about it.
commit ecfd9009-5bae4398b13645e14ec4ce25 (HEAD -> deal-with-snipers)
Author: sunrunner
Date: Thu Jan 22 13:57:34 2026 +0000
Update BidBot default bid cents amount to be 18 (was 16), to deal with pesky sniping strategies discovered on HN.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.
For example, think about "sniping" from the seller side. Sellers are rightly concerned about any wrinkle of the bidding process that might leave money on the table. Automatically extending the time so that every potential buyer has time to "answer" a new bid soothes the concern that buyers were willing to pay higher, but they didn't have the technological prowess to post their bid in the last 0.3 seconds.
You also have to proportionally raise the bid increment, or you'll have people bidding $1 up at the end of every 5 minute period in order to exhaust and frustrate the person they're bidding against. Their opponent's only choices are 1) to mirror the $1 raises, which could go on for ages (then sleep and automation become issues), or 2) to make a big jump hoping that they jump past their opponents limit.
In the case of 2) the dollar bidder's limit could be +$10, and there's no rational way for their opponent to choose the amount for a big jump other than jumping to their limit. Meaning that they just wipe away all of their potential bargain and get it for their valuation. Leaves a sour taste; feels like they're bidding against themselves.
As somebody who auctions things, I use a required greater than "≈10%" of the current bid amount bid increment, and the auction doesn't end on an item until there hasn't been a bid for 10 minutes. Works great. "≈10%" means to just drop the last digit of the current bid to know the minimum next bid. Then I can set the auction to end an hour before I really want it to end; if it hasn't ended by then it's because I mispriced something and the right people found it.
You capture all the value you can, and it runs completely unattended. You just need a way to timestamp bids and broadcast that timestamp e.g. a forum post.
If the winner, instead of paying what they bid, pays what the second-highest bidder bid (and bids are secret until someone exceeds them) then the incentives change. Everyone is incented to bid what it is worth to them, safely knowing (1) they won't pay more than that, (2) they will win the auction if no one outbids them, and (3) they won't pay more than necessary to win the auction.
eBay works this way (more-or-less), so you CAN (if you choose to) simply place your bid any time that is convenient and then ignore the timing of the end of the auction and all the sniping bots.
Meanwhile it's now 100% free to sell on eBay for non-professional sellers.
https://www.ebay.co.uk/help/selling/fees-credits-invoices/fe...
Before: Buyer pays £100, seller receives £100, seller later charged £5 fee, ends up with £95.
After: Buyer pays £100, eBay pockets £5 "buyer protection fee", seller receives £95 with "no fees".
In the last 5 years I've won multiple auctions for not-really-worth-shipping things like bikes, paid via Paypal, then had the buyers contact me to say the fees are too high, cancel the auction and deal separately in cash.
For anything that you're picking up in person anyway, very little reason to use ebay vs. FB marketplace.
Nice:
> You won't pay final value fees or regulatory operating fees
Of course, they will likely find some other way to extract their fees.
It would be nice, however, if the final value fee went away for US non-professional sellers.
There does seem to be no indication (at least on the page you linked) of how they define "private seller", which also opens up the possibility of them defining it so narrowly that, say, only five UK residents ever qualify.
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.
With ubid, you also had the feature of letting it bid to your highest price. Yet they still extended the auction if someone outbid your highest price.
It works quite well!
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.
Huh. I'm a "buy it now" guy and filter out the auctions, but maybe I should start looking for zero bid auctions too.
I don't find auctions exciting or compelling, so I doubt I'd get overly excited about bidding. I'd just set a max bid (probably about half what I would expect to pay with "buy it now", to compensate for the extra delays and hassle involved with auctions) and call it good. If I'm outbid, I'd just do the straight purchase like I would have anyway.
The reason that unnoticed auctions might be worth me looking at is to expand the pool of possible sellers to buy from. Although if my bid makes the auction suddenly attract the attention of automated bidders/snipers, then there's no point to it for me. This might be a nonstarter.
I'll probably give it a try and see how it goes, though.
That's not true. Sometimes there's not a lot of demand and you pay much less than average market price.
If something is priced super low then someone might step in to arbitrage, but even with perfect knowledge in a perfectly efficient market, an arbitrager will only be willing to pay the true value minus the cost of relisting, the cost of reshipping, the cost of their time, the cost of tying up their money, and the cost of the risk it won't resell. If you beat that by fifty cents you'll get a great deal on the item.
This either limits the number of bidders though worse discoverability or just less desirability and lower prices.
You can also save searches for a fixed-priced listing below a specified value, and enable alerts, so that if someone lists something that's priced to sell, you can get it quickly.
i am looking for a bargain not a bidding war. i dont know what is my price ceiling but i know i will only increment twice. if someone outbids me instantly twice in a row i dont want the thing anymore.
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.
I've never really been bothered by "sniping" in eBay. I always bid my absolute 100% maximum, and if someone bids more than me, then they can have it.
Like, if I'm at a store and an item costs $500, and I bring it to the checkout and the cashier says "oh sorry that was mislabeled, it's $500.01 not $500", there is no world in which I go "okay never mind then, $500 was my max". There does not exist a situation where I've decided I want something at price $X, but would not buy it at price $X + $0.01, because $0.01 is absolutely negligible.
So where does this fantasy of an absolute max price come from?
For tricky-to-price items like unique art pieces, the idea that you can pin this down might be a fantasy, but for commodity items it's pretty reasonable. If you can buy the same thing at costco dot com for $500, then it's probably not worth more than $500 to you, and if at auction you get outbid and it sells for $500.01 then you'll shrug and go order the same thing for a cent less, having wasted only a few minutes of your time. If the item you're bidding on is discontinued (e.g. it's last year's model) but you can buy a slightly better one for $550, and you can spare that extra $50, then again you won't be too sad about getting outbid. Online auctions are more popular for used items, but again in that case you usually still have an idea of what a used item is worth to you.
That said, the max price is supposed to be a price where you are not especially happy to get the item at that price, but not really sad either, a price where you would say "well, I hoped for better but I guess that's a fair deal". That's not realistically pinned down to the cent. But if you set a max price at $5000 and would be happy to get the item at $5000.02 (for some reason other than satisfaction from sniping), then you set your max price wrong, or at least differently from how economists expect you to set it.
I think this is the problem. When most sciences observe reality diverge from the model, they see that as a flaw in the model. When economists (at least you HN "economists") observe reality diverge from the model, they seem to see that as a flaw in reality.
The model is wrong.
"I made my max bid $500.01, but I'd have paid $500.02!"
"I made my max bid $500.02, but I'd have paid $500.03!"
…where does this process end?
My phrase "how economists expect you to set it" is probably wrong here, since I'm not an economist, I've just read the most basic theory about how to use this tool, and also used it myself (on eBay, you know, years ago when the site was mostly auctions). So I don't really know what "economists expect", but rather the basic guidelines for using this tool. You got me there.
> I think this is the problem. When most sciences observe reality diverge from the model, they see that as a flaw in the model. When economists (at least you HN "economists") observe reality diverge from the model, they seem to see that as a flaw in reality.
But like, to double-check here: "reality" means your imagined use of a tool that you do not in fact use, right? Like you say you "don't do auctions" and I'm trying to explain what that option is for, and you're countering that the basic "how to use this tool" explanation is a wrong model of reality?
If you're always willing to add one more cent then that wasn't your maximum.
At a shop, usually you're paying less than the maximum you'd be willing to pay, because the shop's prices are fixed and it would be a big coincidence if the price they set happened to match your max price exactly.[1] So even if we model you as homo economicus, it's normal that you're almost always fine with paying $X + $0.01.
In the case where $X really is your max price (i.e. it's right at your threshold of indifference), the idea of rejecting $X + $0.01 seems less silly. You were already very close to deciding $X was too much, so you're probably feeling ambivalent about making the purchase, and the trivial nudge of an extra cent being added to the price might as well be what pushes you over the edge.
[1] There are exceptions, e.g. when you have a negligible preference between brands A and B, so you're defaulting to brand A because the prices are exactly the same, but you would buy B if it were marginally cheaper. But that doesn't affect the main point here.
(And it has to be theoretically false, otherwise $X is equivalent to $X + $0.01 for all X, and so if you'd buy something at 1c you'd buy it for the contents of your bank account.)
If you still dispute this, you need to try to explain how a larger price difference can affect your decision. If you'd happily place a $1 bid, and you'd definitely not place a $100 bid, and a 1c difference could never deter you from placing a bid, then... well, how is that possible?
This process doesn't work endlessly. You can't just add $.01 a billion times and I'd still pay it. But it works once or twice.
Shops set prices like $499.99 due to funny psychological effects: $499.99 is still a price "in the 400s" while $500 is "in the 500s". Nobody sits down and thinks logically about it and concludes that no, the $.01 difference between $499.99 and $500.00 crosses the line. But people see $499.99 and the brain initially goes "oh, it's only 400-something".
- agreeing there must be some threshold such that if the price is $X then you will buy(/bid on) the item, but if the price is $X + $0.01 then you won't;
- but maintaining that in a case where you have already decided to buy/bid and the price then rises by $0.01, you will always go ahead and pay the extra cent (provided this hasn't already happened a bunch of times)?
If so, then I don't see the original problem. Do your best to estimate X (or, more specifically, the value of X you actually endorse as your 'true' valuation), and put that in as your maximum bid. If you get the item at $X you'll be marginally pleased; if you get it for less then you'll be more pleased; and if you miss out on it then you shouldn't mind, as you knew it was only going to be just barely worth it at $X.
If you're actually disagreeing with the first point, then you still need to explain how that can make sense. It's coherent to say that in practice, after making the decision to buy at a given price, you would always accept a 1c price rise but at some point between the first 1c rise and the billionth you'd tell the guy to piss off. But that's not the same as saying the actual value of the item, separate from the emotions involved in the purchase process, is somehow indeterminate. If it's not worth it at $1, and it's worth it at $100, but 1c can never take it from "worth it" to "not worth it", then ?
> - agreeing there must be some threshold such that if the price is $X then you will buy(/bid on) the item, but if the price is $X + $0.01 then you won't;
No, I'm not. If I will buy an item for price $X, I will buy the item for the price $X + $.01. The decision to purchase something is more complex and cannot be encapsulated as one single dollar value.
I think something your model fails to account for is: there is friction associated with a purchase. I will not necessarily go through the process of buying something whose "value" is $0.1 even if its price is $0.09, because there is friction to making a purchase which that $0.01 profit doesn't cover.
As an example: I recently played a Pokemon ROM hack where there was an NPC selling a nugget for 4999. You can sell the nugget for 5000. That's 1 coin profit; objectively a good trade, right? But going through the process of purchasing something isn't free. So in spite of what your economic models may suggest, I did not stop everything I was doing and spend the rest of the game buying nuggets for 4999 and selling them for 5000, because that would've been boring and my time has value.
If I've already gone through a lot of the process to decide to buy something at a certain price (which includes doing research to find out that the thing suits my needs, researching how the market looks for that category of thing, then bringing the item to the cashier or engaging in the eBay auction or contacting a seller), then I've already spent some not-insignificant amount of resources on the purchasing process. A $0.01 price increase will never be enough to stop me from completing that purchase, because $0.01 is not worth going through the whole process again.
If I'm already at the point where I want to bid on an item at $X, then I have spent more than $0.01 in effort researching things to bid on, so I would also bid $X + $0.01.
Yes, that's part of what I was trying to account for with my second bullet point. But before you've made that initial decision, there must be some price that would cause you to make it a 'yes' and some marginally higher price that would cause you to make it a 'no'.
This value obviously won't be totally constant across time -- it will vary with your mental state. But at any given time (and for any given roll of the mental dice, if we're assuming there's some true indeterminism here), it must exist. So when we're translating from "what's the maximum I would pay" to "what should I bid", we can imagine that we're in our most rational and clear-thinking frame of mind, aren't seized by any strange impulses, and so on.
The time and effort of researching a different item also has a value that could be pinned down in a similar way. So it doesn't fundamentally change the arguments here; if product A would be worth $X in a vacuum, but you'd happily pay $Y to avoid going through the research process again, then you should bid $X+Y.
Could there exist some hypothetical subjective value? I mean maybe. But not one that I have knowledge of, so it's not something that can even hypothetically affect my behavior. The only time at which I could possibly be aware of my own subjective value judgement of a product necessarily has to be after I have invested time to evaluate it.
(But also, how is the annoyance not irrational? Your estimates weren't cent-accurate, but they were just as likely to be slightly too high as slightly too low. And you haven't learned anything new about the true values -- unless you take your emotional reaction to be new evidence. For your emotional reaction to be new evidence, it has to be somewhat unpredictable, otherwise you could have fully factored it in in advance. But you seem to be saying that you're predictably going to be annoyed by a 1c loss.)
and so, absolute max price is not a fantasy - the world would be absurd if it were - but instead its a real and difficult to construct value
Imagine someone wanting to pay $3.50 on an auction and them rounding up to $4 to account for cent sniping. You're saying they should bid $4.01, but the bid is already including half a hundred one cent increments beyond the price to avoid cent sniping.
You're saying it's only one cent out of 50 cents. Then you're saying it's only one cent out of 51 cents so you should keep bidding more.
The infinite budget of one cent increments that you're dreaming of is actually finite and probably easier to quantify than the absolute price itself, so you're taking a problem where the hard part has been solved and are now obsessed with the easy part that almost nobody bothers paying attention to.
Edit:
Maybe the context isn't obvious but eBay has an automated bidding system with coarse grained increments for automatic bidding like 25 cents. This means there is a finite number of increments that can be meaningfully cent sniped before getting into the next coarse grain increment. You can't actually win an auction by placing a one cent higher bid at the last minute in an unfair way. Sniping on eBay isn't about winning the item, it's about doing a sealed bid auction where others can't see your price to nibble it up since the automated bidding systems performs a snipe for you at the last nanosecond if you entered a higher bid. There is no meaningful situation where a cent or two is standing between you and the item.
Knowing people bid snipe by bidding one cent over whole dollars, would you consistently bid two cents over if it meant you would win more of your auctions?
One cent is negligible. If you asked me if I would have paid $10.01 instead of $10.00, I'd probably say "Sure". $10.02? $10.03? Like, where does the line get drawn?
And then you come at it from the other way. Let's say I'd pay $10, but not $11. But what about $10.50? $10.25? Or we can go down by pennies again.
I agree, put in your limit and walk away. If you get overbid, even by a cent, don't sweat it. That's the game. But I can see why people get frustrated when they lose an auction by one cent.
This would let people stop thinking "I lost by one cent" in that situation. It also has a marketing benefit: look at all these people who got great bargains relative to what they would have paid. And it's not an unreasonable amount of transparency: in second price auctions e.g. for stamps or electricity, it's normal to publish the details of all the bids.
Of course eBay has already thought about this more deeply than me and perhaps trialled it and decided they didn't like it. Maybe it's off-putting to sellers to see they lost something for $10 to a buyer who would have paid $30?
If the current price is $5 and your max bid is $30 and I put a max bid of $100, it will make the current price $31 - $35, whatever the increment is.
To get ebay to accept a bid of one cent over, you have to explicitly set that. Let's say, I'd actually pay $30 as well. $30.01 isn't materially different. So if I put in $30.01, my bid becomes higher than yours.
In fact, I'm somewhat angry at sellers setting up auctions if there's no other way to acquire a specific item. Why they won't put a minimum price they're happy to part with some items for, instead of wasting time of a lot of people by withholding target price and pretending they're earning premium through work?
Also some sellers seem to use some fake accounts to bid high on their own item, revealing your max bid, then cancel their bid, then bid right under your max bid to maximise their sell price. Happened to me twice, and now no longer setting my max bid in advance since.
The 'nibblers' will invariably show up and bid small amounts until they exceed your maximum bid, while not revealing theirs.
A bidding war can make the perceived value of an item increase.
People's competitive behavior, or "you're not taking this from me," or "I've definitely got this item and have made plans" or any number of other emotional behaviors take over.
People's railing against sniping also demonstrates this.
- 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.
The only way auto-bid could hide information is if eBay treated auto bid as "silent auction" style. Show "zero bids" all the way to the end, then once closed, see which 'auto-bid' came in highest and declare that bidder the winner.
Sniping is attempting to recreate 'silent auction' style bidding, with a bid system that is not 'silent'.
Sure, I've been outbid at the last moment. Losing an auction is always a little frustrating. But if I was willing to pay that price I should have bid it myself. Feels fair enough?
Since, from the outside, it surely sounds like you get pleasure by inflicting some form of suffering on others. But that hopefully isn’t considered fun, is it?
Globally, wealth gets created, which leads to a positive-sum game, not a zero sum game.
On the other hand, if one quadrillionaire in a city owns all the money available in that said system except 100 currency units, the remaining 100 humans are in possession of exactly 1 currency unit. The suffering for the 100 humans is significantly higher for the 100 than for the one, even though it fulfils your premise of a balanced global suffering index.
Before the trade, the value for the seller and the buyer was zero. Whatever the trade involved, the moment the minimum of the seller gets hit, it becomes a positive-sum game.
If this would not be the case long-term rise of stocks would be impossible. That would mean a stock rise is a redistribution and you take it away from someone else . So, if the stock market were truly zero-sum, every currency unit earned would require someone else to have lost one.
> if one quadrillionaire in a city owns all the money
That's a valid risk factor but on a random eBay purchase I think it's fair to say we have no idea if the purchaser or the seller gets more utility out of each dollar.
>we have no idea if the purchaser or the seller gets more utility out of each dollar.
Assumption: the seller opened the auction with his actual hard lower limit, he should be happy with what he gets as soon as that limit gets hit.
The original poster said that he essentially altered the bid in favour of the seller. However, the exchange of subjective equal values is based on the balance between the two parties and now gets distorted in favour of the seller and in detriment of the buyer. This should result in win/lose if I am not mistaken.
So, maybe I get you wrong, I am not sure right now.
My argument is that this distortion in favor of the seller isn't really good or bad in a meaningful way. It's just rude.
The seller is happy as long as their limit is hit, the buyer is happy as long as their limit isn't hit. How should the surplus happiness get split? I dunno. So the earlier poster sticking their finger in and shifting the surplus around isn't a particularly moral issue.
If there was never a worry about this, they could bring out (and decide) that ceiling only after being outbid.
And this probably appears to work enough times in the snipers favor to trick them into thinking it is a winning strategy, whereas they likely would have won the same auctions in the end by just bidding that 'minimum' as their maximum bid. But as they can't easily (i.e., without expense) A/B test their strategy, they get no feedback that sniping isn't really helping them like they think it is helping them.
There also isn't really any detriment. At worst, the sniper is making the same bid they would have made otherwise. If the opposing bidders are not purely rational, and have not put in their actual maximum bid, then sniping can deprive them of that opportunity and thus lowers the hammer price.
And bidders are not purely rational, especially when the items are not purely utilitarian. Getting notifications that you have been outbid has an emotional effect, as does having time to think about raising the bid.
I can only hope.