Sending out snail mail seemed worth trying (we did a 5000 piece post card mailing to a group of very likely to buy parents), but learned the hard way that we probably would need to do this repeatedly for it to pay off.

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Nextdoor verifies each person's address by using one of four methods: credit- or debit-card number, landline phone number, mobile-phone number or by mailing a postcard that includes an invite code.

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