It is not a giveaway for me looks a raffle with some users always winning. not provably fair. 
Some users winn often while some others less. I even issue code missing the 2 last digit, so need to try 99 number to get it...I cannot make it more random...
This could be explained as some users are on our website 12 hours daily and sucess to get more code than users present only few minutes and not seeing any code. I guess this fair in the way we make this giveaway to promote crypto-trade.com.