ecco cosa ho trovato:
Q: How long is a travel authorization via ESTA valid?
A: Each approved ESTA application generally is valid for two years and allows for multiple visits to the United States within that period without having to apply for another ESTA approval. Travelers whose passports will expire in less than two years will receive an ESTA valid until the passport’s expiration date.
A new travel authorization is required if: (1) the traveler is issued a new passport; (2) the traveler changes his or her name; (3) the traveler changes his or her gender; (4) the traveler’s country of citizenship changes; or (5) the circumstances underlying the traveler’s previous responses to any of the ESTA application questions requiring a “yes” or “no” response have changed. The associated fee will be charged for each new application submitted.
Q: Can prospective travelers apply for an ESTA without specific travel plans if they want to be able to travel to the United States later on short notice?
A: Yes. VWP travelers are not required to have specific plans to travel to the United States before they apply for an ESTA. If a traveler’s destination in the United States is unknown when he or she completes the ESTA application, the traveler should enter “Unknown.” Travelers may update this information when their plans are finalized, but they will not be required to update their destination addresses or itineraries should they change after their ESTA application has been approved.
Quindi sembrerebbe che ci poniamo troppi problemi per questo ESTA.La unica cosa che serve a loro è sapere nome e numero di passaporto in maniera da velocizzare i controlli e basta,,,sbaglio?