Most of the winners of duelbits giveaways are those Twitter users that are active in joining different casino giveaways on twitter. I think some of them are using multiple accounts to join in the giveaway since I check that some user has the same history of the contest they are joining. It's really hard to win on this kind of unmoderated giveaway that is full of bots twitter accounts unlike here in the forum that only high ranks can join or at least newbies that already proved that they are really playing on Duelbits.
I hope Duelbits will do the same giveaway here even with low rewards than twitter. Twitter is full of bots user that taking advantage on having multiple account to increase there win chance rate.
For sure there are so many bots that grab this offer as soon as they land on twitter and people have multiple accounts to have the random giveaways on their any of the account.So your chances are really low and also the amounts are low so don't feel bad for it but yes from team they are giving out it on regular basis which is good move.