<b>Soft floors, hard floors, and why first-price killed the trick</b>

<b>Soft floors, hard floors, and why first-price killed the trick</b>

A price floor is the minimum a publisher will accept. There were historically two kinds, and the distinction used to be exploitable.

1. A hard floor rejects any bid below it. Simple.
2. A soft floor (under second-price rules) was a threshold below which you paid your own bid, and above which you paid second price. Clever buyers bid just over the soft floor to win cheaply.
3. With the move to first-price, the soft-floor game collapsed: you now pay your bid regardless, so there's no second-price discount to engineer toward.

What remains is a strategic interaction between your shading engine and the publisher's floor. If the publisher sets a dynamic floor that learns from your bids, and your shading learns from clearing prices, you have two adaptive systems pushing against each other. Floors can ratchet up to capture the surplus your shading was trying to keep.

<b>Why it matters:</b> dynamic floors are why a publisher's effective CPM can rise even as the open market softens — the floor is harvesting the gap shading leaves. When a specific publisher's clearing price climbs against the market trend, suspect a learning floor and test how your DSP responds to floor signals in the bid request.