Pretty straight forward deal as per the email I received.. Doesn't say anything about existing customers not being eligible.
- Download and sign up to the free GROUPON App
- Enter the code word “BEGIANT” and get $20 credit – it’s that easy!
$20 OFF is valid on any purchase of $49 or more on the Groupon App Only. Offer is valid until midnight 1st December 2017. Valid 1 per customer and cannot be used with another discount promo. The discount will be applied to one single voucher and not the basket amount
Was going to get a $59 dinner for 2 meal few days ago when they had 15% off, lucky I waited to score it for $39. Thanks OP!