There is a new promotion by MetaWin for today only. Until 6 September 23:59 UTC it's Diceback Hour!
Deposit $10 using promo code DICEBACK and get 50% cashback on all real-money losses up to $100. This promotion is valid for only 60 minutes after you have made your deposit. You can only wager it on Metawin Dice.
I just tried this offer. Initially I turned my deposit amount to 2.5× almost. I was looking for $10 more before stopping and cashing out the funds. Unfortunately, my luck faded at that moment and I had lost my deposits. Then I have also lost the 50% cashback amount. It would have been better if I didn't look for the $10 more.