Why a stranger ships to you first

Escrow is the whole reason the order works at all. On Nexus it is 2 of 3 multisig, which means no single person can quietly walk off with your money.

When you pay for an order, the coin does not go to the vendor. It goes into an escrow address that needs two of three keys to move. You hold one key, the vendor holds one, and the market holds one. That structure is what lets you send money to someone you have never met and expect the deal to hold.

The normal flow

You fund the order and the coin sits in the multisig. The vendor sees it is funded and ships. When the package arrives and matches, you confirm receipt, and your key together with the vendor's releases the payment. Neither the vendor nor the market can take the money alone at any point in that chain.

When something goes wrong

If the package never lands or arrives wrong, you open a dispute instead of confirming. Now the market's key is the deciding one, and staff weigh what each side can show against the vendor's history. This is another place the market's depth helps, because a vendor with hundreds of clean orders and one with a bad week do not get read the same way.

The one move that undoes it

Finalize-early means releasing the money before the goods arrive. Some vendors ask for it. On an unproven seller it is just handing over your coin and deleting the dispute button at the same time. Let escrow work. Confirm receipt when the package is in your hands and correct, and not a moment sooner.