Plausible deniability? I feel like sending a literal rock puts a banner on it for being a scam but something that looks like the chip although doesn't function leaves lots of room to argue & misdirect: the issue is elsewhere with the receiver's computer setup, it was installed incorrectly, a legitimate CPU was sent but was damaged in transit or by the user and has no warranty, etc.
The vast majority of buyers do not have the ability to open up the CPU and tell what they're looking at. OLX presumably does not want outright scams but also doesn't want to put any effort into warranty, returns, customer service, etc. You mostly just have to make it murky enough I would guess.
I still don’t understand how they make any money from this, who wouldn’t immediately dispute the purchase if they put the CPU in their PC and it doesn’t boot? As a customer, I don’t really care what happened to the product before if it arrives and it’s broken. I ask for a return and if the seller gives me trouble, I do a dispute with PayPal and get my money back. I don’t even have to diagnose the issue.
I understand that OLX is like Facebook marketplace where how money is transferred is up to the buyer and seller, so often it's transferred in a way that doesn't enable disputes. For e.g. in Canada if you etransfer someone you have no way to dispute the transaction.
The vast majority of buyers do not have the ability to open up the CPU and tell what they're looking at. OLX presumably does not want outright scams but also doesn't want to put any effort into warranty, returns, customer service, etc. You mostly just have to make it murky enough I would guess.