Denial of inventory happens when automation holds or exhausts available stock so genuine buyers cannot complete a purchase.
The goods may never be paid for, yet they disappear from sale while carts, reservations, or repeated checks keep them locked.
How it works
Scarce items are especially exposed, because a script can open many sessions and sit on stock faster than people can decide.
The shop then shows an empty shelf, refunds nothing, and later releases the goods when the holds expire, often after real customers have left.
This is an availability problem for merchandise rather than a flood against the network.
Fair limits on how much one client may reserve, delays that raise the cost of repetition, and review of odd holding patterns protect buyers without publishing a method for hoarding.
Concrete examples
- A limited product shows as unavailable within seconds of release while completed orders remain a small fraction of the holds.
- Dozens of reservations from similar new accounts expire together an hour later, and the stock returns unsold.
- A genuine customer watches a size vanish and reappear repeatedly without any corresponding paid invoice.
Protective measures
- Cap how many units one client may reserve, and release unpaid holds on a short timer.
- Review bursts of reservations that do not convert to payment, and challenge clients that create those bursts.
- Separate browsing from the act of locking stock so a page view alone cannot remove an item from sale.
- Tell customers when a hold expires so they are not left believing the item was truly sold out.
How CDPCaptcha helps
Proof of work raises the cost of scripts that reserve stock without a genuine completed purchase.
CDPCaptcha is a self-hosted proof of work check in the browser, with no cookies, no tracking, and no picture puzzles.
It is made and hosted in the EU, in Germany, and the service is described at https://cdpcaptcha.com/.