ebay finds that PWCC engaged in shill bidding?

[Snowman]

Originally Posted by Peter_Spaeth

This is the Blowout thread on PWCC cards supposedly not paid for I referenced the other day.

I probably posted it here a long time ago but worth another look in light of the recent ebay claim.

https://www.blowoutforums.com/showthread.php?t=1307889

This is precisely the sort of analysis that drove me nuts over at the Blowhard forums. Somehow, someone thinks they can "prove" that they've discovered a way to uncover this damning list of manipulated transactions because they found cards on PWCC's research tool but those cards were absent on eBay's. There's a huge problem with this assumption though. eBay's data integrity is absolute garbage to begin with. I deal with data integrity issues every day at work. It's an extremely important aspect of a data scientist's job. Every company has these issues. You can't just assume that what pops up in eBay's market price research tool is comprehensive of anything, and the same with PWCC's tool. You can't look at the intersection of those two datasets and start making conclusions like this about the missing links. There's often no rhyme or reason to which cards get listed as "sold", which ones get removed or flagged, when the ones that do get removed actually get removed, etc. Just go look through your own eBay purchases and try to see which ones you can find through their market research tool and PWCC's research tool. You will find missing sales. It is extremely common.

These sorts of threads are tattooed all over the place at Blowhard. Then the subsequent posts are just an avalanche of praise from people who just gobble this nonsense up. "Oh wow! Great work detective!"

Don't get me wrong, I'm not saying shill bidding doesn't happen on the regular with PWCC consignors, or that some of these cards weren't paid for. I'm just saying that this list isn't what you think it is. The primary conclusions from that thread are not valid. Also, just because an item wasn't paid for doesn't mean it was because of shill bidding.

Here's a prime example from my own collection. And this is for a 52 Topps Mickey Mantle no less. I bought this card on eBay from PWCC on 07/22/2021 for $45k. But it doesn't show up in eBay's market pricing tool. Yet I assure you, it was paid for and is currently in my possession.

Same with some of my other recent purchases. I bought 3 1986 Fleer Michael Jordan SGC 9 rookie cards, all on eBay from PWCC. But only 2 of the 3 show up. Why is that? Again, all were paid for and all are in my possession.