Sellers pay a refundable listing deposit (10% of their listing price) that's meant to keep them accountable for not listing illegal items and following the rules of the sale.

For reference: https://satscrap.com/seller-guidelines

Of course they're immediately refunded the deposit when they cancel the listing or when they deliver the sold item.

Sats as collateral means we don't need a bunch of invasive personal info from the seller and it enables a much easier/faster listing process as long as you're familiar with transacting BTC (esp over LN).