I can make sure for everyone, that the code sharing is not based need wagering every week or something like that. Because my last deposit duelbits is on March. This is my claiming code, I just claim 2 codes from Mei still work even if the code is old for more than 72 hours.
Yeah they are random one's like you have not deposited from a long time and some who are active also didn't get this $5 coupon so we can assume it's just to some lucky players.So it is applicable even after 3 days also giving players chance to redeem it if they haven't looked at the mails for few days.