What happens to a buyer who wins an auction but doesn't pay?

[tonebigkidzone]

Do deadbeat buyers get a negative mark against their name for not paying for a winning bid?

[quiltgeek]

Yesm if the seller files an Unpaid Item cancellation with eBay, the buyer get an Unpaid Item Strike. A buyer with 2 or more strikes will find that some sellers automatically block potential buyers for having too many UPI Strkes.

The seller in a transaction can also put the buyer on their Blocked Bidder List so that buyer can never buy from that seller again.

[woodland_gnome]

Also it counts towards his/her Open Transaction Limits for some period of time, and is grounds to lower his/her limits.

Note that it does NOT appear in his/her public profiles.  The "mark" is not publicly displayed but it does count when the seller has set up his/her Buyer Requirements to block buyers with multiple strikes in the past (up to 12 months).