Just got this in my email.
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The answers to the quiz credits to @altomic
canada - hawaiian pizza
matt damon - mystic pizza
macauley caulkin - pizza underground
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Join Microsoft Rewards, take a three-question quiz and claim a voucher code for a free* Domino’s Traditional Range pizza, on Microsoft! Subject to limited availability.**
*Free Domino’s Pizza voucher is subject to limited availability, offer expires the earlier of 30 November, 2017 and the date that no Domino’s Pizza vouchers remain available. Voucher code is valid for one use only and expires 28 February, 2018. The code must only be redeemed online at dominos.com.au or via the Domino’s iPhone, iPad or Android App. Not valid for redemption via phone order or orders made in-store. Not transferable or redeemable for cash. Selected stores only. A surcharge applies to upgrade to premium pizzas, half ‘n’ half, additional toppings, indulgent crusts and promotional products. Minimum delivery order $22. Drivers only carry $20 in change.
**If you join Microsoft Rewards at the link above and complete a three-question quiz, you will be taken to a redemption page where you can opt to receive a voucher code via an email from Microsoft for a free* Domino’s Traditional Range pizza. This offer is not open to current Microsoft Rewards members and is limited to one voucher per person. Microsoft may withdraw this offer with 24 hours’ notice, which will be posted here.
via Dominos Facebook
Probably means you've signed up to Rewards on that account before. Happened to me.
edit: ninja'd slow internet