RTBlintAlpha
Loss reason 104: Buyer Seat Blocked
What it means
The publisher or exchange blocks this seat on this inventory.
The exchange reports this code by expanding the ${AUCTION_LOSS} macro in the bid's loss notice URL (lurl). A bidder that does not set lurl never sees it, and never learns why it lost.
What to do about it
The bid was valid and lost on price or eligibility: below a floor, outbid, beaten by a deal, or seat-blocked. The response side is fine; the lever is bidding strategy. Log AUCTION_MIN_TO_WIN wherever the exchange expands it, and check floors and deal terms in the request before pricing.