Final answer:
Generally, a seller should receive a copy of the listing contract immediately upon execution, which is 'on the spot'. The provision of the contract allows the seller to have proof and review the agreement's terms whenever needed.
Step-by-step explanation:
When a listing contract is signed, it is customary practice for the seller to receive a copy of the contract as soon as it is executed, which would generally be on the spot. Real estate laws and standard practices can vary by location, but generally speaking, once both parties have signed the contract, each is entitled to a copy immediately. This ensures that the seller has proof of the listing agreement and can review the terms at any time. If the contract were digital, it should also be provided immediately, whereas if a hard copy is required, it is typically handed over during the signing or sent shortly thereafter.