Sure, sure, and next you'll tell me there's a way to know which side of the car the gas cap is on.

This reminds me so much of an old World of Warcraft addon i used in 2005-6 or so… I believe it was called ‘bottom feeder’ or something.

Basically, you would leave your character logged in sitting at the auction house. It would observe auctions for a while, and generate pricing data and sales data. Then, you would enable automatic mode, and it would automatically bid/buy any item that someone put up for sale if the price was much lower than normal.

You would leave it running overnight, or whatever, then come back to go pick up all the items it bought, and then you would go back to the auction house and sell all your items you bought at the correct price.

Basically, you would see buy auctions created by people who didn’t realize what the correct price should be and sold too cheaply. Since this was an automated system, you could beat any human to take advantage of the deal.

I made a ton of in game currency doing this.

After a few months they changed the auction rules to prevent this… add-ons could no longer directly bid on items, and you had to sit there and click “buy” whenever the script found a good deal. This severely limited the amount you could make with the script.

Basically this mirrors the eBay timeline, with the same reasons I am guessing… eBay (like WoW) doesn’t want bots collecting arbitrage.

> the AI could also create the listing as soon as the item is purchased.

There are businesses doing the other way round: list a bunch of stuff, then once an order is placed find the item to fulfil it with.

I can't think of a scenario in which me buying some used stuff on ebay is that serious to be honest, having the AI buy would be a huge risk as well.

> Also if this were a business and you were going to resell it the AI could also create the listing as soon as the item is purchased.

That sounds like an awful grift, but good point, people might use such a system for that.

I found this interesting to think about. On the surface, this could fit the requirements. However, in the past decade, I feel a dynamic where my relationship with tech companies like eBay are actually antagonistic, rather than cooperative. They (and American society) have become so extractive and user-hostile that I have no trust their features are designed to accomplish my goals. Instead, they are designed to accomplish the company's objectives and it's only by coincidence if the customer is satisfied.

Yeah that's very possible, I have never built anything with LLMs and I'm not a heavy user so I'm not sure how feasible it is.

I do think I would already get value from a least worse option every day, a sort of 'digest', so I don't have remember, and to look through results myself. I think it's a best case for LLM use for me, there is no harm at all in false negatives or positives, there are no significant stakes and I think the vagueness / unpredictability of the output is an advantage, it might find something that I had not even considered (like for my example: here is a used laptop with roughly these specs, it could also be a good home home server, something like that).

> 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.

> Bidding is open as long as there have been bids in the past 5 minutes.

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.

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.

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.

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.

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

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.

Wow. I remember Ubid, and I bought several things from it. It would become problematic when folks would bid up things far beyond the starting price.

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

Pretty much every auction platform I've seen, except eBay, extends listings by a few minutes every time a bid is received.

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!

Japanese auction sites work this way too.

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.

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.

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.

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.

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.

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.

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.

Reddit.

Except speed and "translate the following to klingon", etc

This. I was selling an obscure book once. I doubt there is anyone local that would be interested in it. It was sold on eBay within a week.

Same for a half functioning Xbox. No "normal" person would want that. But apparently, on eBay, something like a dozen people took serious interest in it, and it was sold in a few days in "parts only" condition. For sure I didn't like how much the transaction fee I paid, but at least I got rid of it for a decent amount of money.

Even if they use Paypal?

Sure,

I listed the item as $185.00 + $10.00 shipping.

Order total = $195.00

- Transaction fees = $32.44

- Postage label = $14.65

Postage I can understand.

> But it is also ebay's right to decide whether or not its computer will allow requests from your computer.

That is dangerous thinking right there: Ebay does not have rights.

Of course ebay may do it anyway, and it may take time for justice to correct things, but it is not Right, nor their right, to violate law even to protect themselves.

Then most websites can sue OpenAI and Anthropic, but in reality, they can't.

I have decent tech company salary but I don't even buy $10 books without checking everything. This week I almost bought a wrong book (manually) because how similar the title is. Automating stuff with AI is interesting, but I don't want the hassle of getting surprised and handling returns, if the item can be returned at all, especially on eBay.

I genuinely wonder, would you do that, really? Sure 600$ is not the end of the world for certain countries, but neither it is a sum I'm willing to just lose on random. What if the electronic parrot buys from an obvious counterfeit vendor or obvious scammer? Or what if it buys you a stratocaster but different? Or a random 1982 guitar? What if it ignores 600$? Or what if it buys 600$ item with 300$ shipping and 500$ customs from god knows where?

I've seen enough by now and I know that some people will just unleash LLMs on anything without almost no oversight. We can already see people use agentic IDEs with "do all the shit" flag, they would probably easily add finances to the list of automation.

But, honestly, would you?

Yeah I guess that makes sense for some people. I'm just not in a financial position where I'd let an AI buy a $600 used guitar without me taking a look at it first.

Yeah literally price mistakes being picked up right away. But also seems like a good way to get scammed.

[Recycling a joke from many months ago]

My mistake, you're completely correct, perhaps even more-correct than the wonderful flavor of Mococoa drink, with all-natural cocoa beans from the upper slopes of Mount Nicaragua. No artificial sweeteners!

(https://www.youtube.com/watch?v=MzKSQrhX7BM&t=0m13s)

But that also seems like a very inefficient way to accomplish this automation task from the drop shippers side too. What do you gain from the LLM that non LLM automation couldn't do more cost effectively?

You would really do this? You'd not even want to at least briefly review the cart before making a $600 purchase of used computer hardware?

You will end up with expensive scam parts.

"Buy good quality for less than market value and don't get scammed" is so far beyond AGI complete that I cannot fathom how people think it will be reliably doable by LLMs

I think it's telling though how everyone's example of how an AI agent can help you shop is "I want it to take advantage of someone else's mistake or knowledge asymmetry to make me free money".

Are you all just embarrassed used car salespeople?

Not commonly known (I work in this space), but yes.

Agents are being used to automate things like non-cash account balance arbitrage, stacking and abusing marketing promotions, triangulated purchasing schemes, and purchase-refund arbitrage schemes at an increasingly large scale.

They may have an inkling that the big LLM companies will want to pay for future/past data... I imagine either Google or OpenAI has something predictive and shopping-related in the books.

This; "certified / authorized by eBay" and then agents have to pay access to the catalogue

Yeah, they're hedging against "AI purchases". eBay has already been dealing with automated/bots for years.

> Ebay doesn't want to deal with charge backs for hallucinate purchases

A charge back doesn’t mean buyer always wins. Imagine if credit card companies also pass a rule - “LLM or AI purchases are non-refundable”.

On a different note - once I tried to cancel an eBay order within a minute, both eBay and seller declined. It’s so fked up with them.

No, but when instituting bullshit policies or trying to regulate natural/normal behavior for selfish gain, it helps you if you can enforce the policy, otherwise people will just ignore it.

LLMs don't need browser automation though. Multimodal models with vision input can operate a real computer with "real" user inputs over USB, where the computer itself returns a real, plausible browser fingerprint because it is a real browser being operated by something that behaves humanly.

I don’t know if there are other ways eBay could lose money on returns. But my single data point: the very first thing I sold on eBay (a manual lever espresso machine) got returned because the buyer clearly didn’t know how to use it, and claimed it was defective. And because eBay has a money back guarantee, they just reached their hands into my back account and withdrew the earnings from the sale + the shipping costs for the delivery to the buyer + the shipping fees for the return. They even kept their listing fee and the sales tax. So… I don’t think eBay stands to lose money directly from returns. Maybe they risk pissing too many sellers off with an increased rate of this horrific experience?!

"Mint condition MacBook Pro M5, 64GB RAM, 2TB storage, midnight black, box only" and it sells for $1800 because someone didn't see "box only".

An AI-Agent browsing eBay for a "widget" for a given individual will also likely not be browsing eBay's advertising listings (sponsored and promoted listings [1]) which would potentially equate to a loss in ad revenue for eBay. So there is likely a "protect the advertising moat" aspect to their "ban" as well.

[1] Given how hard eBay pushes sellers to purchase the sponsored and promoted listing tiers (at an additional fee of course) implies they make some nice revenue stream from these advertisements.

This assumes the LLM ecosystem stays centralized. Open source models running locally or on user-controlled infrastructure flip this - the agent works for you, not for whoever pays the model provider.

The race is already happening: open weights models are getting good enough that "your personal shopping agent" doesn't need to phone home to a company with ad incentives. The future probably looks more like ad blockers than ad platforms - agents that aggressively optimize for user preferences, not platform revenue.

Or if eBay blocks ChatGPT while Amazon doesn't.

Open source models can short circuit that hopefully.

Fewer companies get the chance to enshittify my experience? Sign me up!

>The marketplace that builds "agent-friendly" commerce (verified listings, structured data, transparent pricing, API access) becomes the default backend for AI shopping.

I'd like to believe this, but claims like this have been made since the early days of internet commerce. After all, it's not hard to specify structured data about items and run queries against it. But it largely has not materialized outside of a few special suppliers.

You can't actually search Amazon or eBay or Wayfair for things with specified dimensions or characteristics. You can, however, find lots of listings for things like "Gzsbaby 6 Piece Jumbo Dinosaur Toys for Kids 3-5 and Toddlers, Large Soft Dinosaur Toys for Lovers - Perfect Party Favors, Birthday Gifts "

Perhaps this time is different? But why is it different? What economic incentives will lead to good structured data and transparent pricing, rather than whatever the AI equivalent of glurge/slop listings is?

Comment definitely reads like AI

Stop the ai witch hunt madness

I didn't catch that on first read, but I see why you'd say that. LLMs are ridiculous in the constant usage "it's not X it's Y" -- It's in almost every response from Opus 4.5. "It's not X it's Y" is ruined for regular writing.

I'm also skeptical of anything that claims to reliably detect AI writing. FWIW, I plugged the comment into Pangram Labs, which claims to be the most reliably and seems to have worked well before. It categorized the comment as 100% human written with medium confidence.

What does green name signify on HN? I've always wondered.

This slop so annoying to see, and tiring – but worth it here – to call out.

Dead Internet theory

100%.

Hallmarks of AI or AI slop? Or are you suggesting that AI is slop by definition?

Let's assume it's a bot. Is the point it's making unreasonable? Is it really unreasonable to refer to eBay's listings as inventory?

Yeah, it really says something about the state of HN these days that this account racked up (net) 261 votes in nine days writing absolute drivel.

The bots are learning to defend themselves on social media

Seriously, how is this the top comment?

But, ads directly correspond to revenue stream, and a loss of ad "impressions" would result in a reduced revenue stream, so a "protect the advertising" response is not at all unusual to consider as a portion of their (eBay's) reasoning for this ban.

Given how hard they push sellers to purchase their "extra cost listing enhancements" (i.e., purchase to have your listings show in the "advertisement" spots) it appears that they may make a decent revenue stream from these advertising angles. An AI-agent could find listings without going through the advertising displays and as such cut into this revenue stream.