View Full Version : Shill Bidding Idea
iambison
11-25-2025, 04:41 PM
I'm sick of getting robbed by shillers on ebay, so I've been building an product to protect myself on ebay.
- Instantly exposes bidders who only bid with one specific seller. A clear indicator of shill accounts used to drive up prices artificially.
- Figure out if bidders reputation was built on ebay with shady methods.
- Detects specific bid timing patterns designed to 'test' your max bid without intent to win.
-See the real market value. We automatically filter out outliers and flagged shill sales
Can you comment if you would use it, or if they are other things you are doing manually that you want to see automated.
Would be free to start.
jcardstore
11-25-2025, 04:51 PM
So I believe in the “bid what you’re willing to pay” method.
Unless eBay decides to do something (they won’t) exposing shill bids doesn’t really accomplish anything
I guess I just don’t see the value proposition. You’re not going to be able to identify any bidders anyways
asujbl
11-25-2025, 04:56 PM
Nope
Because you can do all this without whatever you are offering… which won’t be free for long… which is why you said “to start”
It’s super easy to figure out shill bidding if you have any common sense
iambison
11-25-2025, 04:58 PM
I was just going to build it for myself so I don't have to manually check some of the auctions to see if shadiness going on. Especially for recent comps. But ya you can do it yourself.
I would not be trying to make money off it. More just to flag quickly like this auction has a ton of shill bids, or this one that finished isn't a real "purchase"
Anyways appreciate the feedback so far. I just hate what is happening and that people are getting scammed, never investors/collectors but ultimately its on ebay. They could be stricter if they wanted to. have had some friends new to the hobby fall for fake sales etc. so thinking if any solution or you just have to develop taste and wisdom over time.
Stackfan
11-27-2025, 08:01 AM
So I believe in the “bid what you’re willing to pay” method.
Unless eBay decides to do something (they won’t) exposing shill bids doesn’t really accomplish anything
I guess I just don’t see the value proposition. You’re not going to be able to identify any bidders anyways
The hobby has been brainwashed with comp's... but i suppose that's a good way for new collectors to learn, and not over pay. Except scammers can manipulate that, so it's best new comers stay away from high end, which is the most manipulated.
I would think a majority of veteran collectors tell if cards are over/under priced. The shill bidding definitely makes it harder.... but when you take into account all the major factors that goes into the price of the card (Player, set, type of card, rarity, condition, hype etc) it'd easier to see through the weeds.
The best deals are on the stuff no one is looking at. Guess it all depends what you want to do with the card too.
oldgoldy97
11-27-2025, 09:12 AM
I applaud your efforts. Gotta start somewhere.
dizzy4111
11-27-2025, 10:00 AM
I would you use it. I would also give side eye to anyone that pushes back on this idea if it's done correctly.
Orangejello727
11-27-2025, 02:27 PM
just make all listing BIN or best offer. Done
blackvodka
11-27-2025, 02:58 PM
just make all listing BIN or best offer. DoneGod I wish.
Sent from my motorola razr 2024 using Tapatalk
iambison
11-27-2025, 05:29 PM
I'll keep everyone posted, looking to solve this one since I think its important and annoying to do manually.
Instantly exposes bidders who only bid with one specific seller. A clear indicator of shill accounts used to drive up prices artificially.
Orangejello727
11-27-2025, 05:33 PM
God I wish.
Sent from my motorola razr 2024 using Tapatalk
i just bid on BIN and best offers. Never put bids on auctions
GuacamoleCards
11-28-2025, 01:25 AM
I'm trying to understand your intended use case... is it so that you can eliminate certain completed auctions from comps?
PuddleMonkey
11-28-2025, 02:13 AM
Just gonna leave these here, no rhyme or reason.
https://i.imgur.com/80oBJSy.jpg
https://i.imgur.com/x8QZFap.jpg
https://i.imgur.com/PdiI4Fn.jpg
https://i.imgur.com/mGm7AGD.jpg
https://i.imgur.com/Sk1A1Cg.jpg
https://i.imgur.com/7MiQsRB.jpg
https://i.imgur.com/IIGyLjS.jpg
https://i.imgur.com/YT3SoSq.jpg
https://i.imgur.com/6migvIY.jpg
https://i.imgur.com/c6jdKoY.jpg
fabiani12333
11-28-2025, 09:11 PM
Anyways appreciate the feedback so far. I just hate what is happening and that people are getting scammed, never investors/collectors but ultimately its on ebay. They could be stricter if they wanted to. have had some friends new to the hobby fall for fake sales etc. so thinking if any solution or you just have to develop taste and wisdom over time.
Unfortunately, you have to have a very cynical mindset to operate safely in this hobby -- scams, fraud and manipulation seem to be the norm. It's not a good place for average people -- they don't have the right mindset to safely navigate it and are targeted by scammers because of their ignorance.
fabiani12333
11-28-2025, 09:15 PM
So I believe in the “bid what you’re willing to pay” method.
Unless eBay decides to do something (they won’t) exposing shill bids doesn’t really accomplish anything
I guess I just don’t see the value proposition. You’re not going to be able to identify any bidders anyways
The problem is when there is rampant shill bidding and price manipulation, there's no way to really know how to properly price cards -- comps are not reliable. So, you may be willing to pay a certain price for a card, but it's based on fake comps. Only later on when prices drop do you realize you paid more for a card than you otherwise would have.
jcardstore
11-28-2025, 10:08 PM
The problem is when there is rampant shill bidding and price manipulation, there's no way to really know how to properly price cards -- comps are not reliable. So, you may be willing to pay a certain price for a card, but it's based on fake comps. Only later on when prices drop do you realize you paid more for a card than you otherwise would have.
If you’re buying something with the intention of reselling it then sure, you should be thinking about what it’s going for. But also, then just do some basic due diligence it’s not hard
It takes me less than 5 mins to price a card.
But if it’s for a PC who the hell cares what comps are?
Archangel1775
11-28-2025, 10:47 PM
The problem arises when you end up attempting to use it on large consignors. Some people just dont want to bid with other sellers. COMC is another one where they have auctions. Some people only use COMC.
Harper
11-29-2025, 09:14 AM
The problem arises when you end up attempting to use it on large consignors. Some people just dont want to bid with other sellers. COMC is another one where they have auctions. Some people only use COMC.
Oh I would say the opposite. If you only bid on consigner auctions it would be the biggest red flag possible.
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