That's another tactic the scammer used. He usually gave winnings to a circle of accounts that were managed by him. When you try to compare the losses of the accounts to wins, the wins would be more. He did this to entice his victims.
They do this in the telegram channel, they message you with this kind of offer, they will make it appear that you will both win in this transaction, by depositing and making you win, be careful on anyone messaging you, just ignore them or ask them to message you here in Bitcointalk and check if he has good standing here in Bitcoin.
Agreed, and this will be done with creating new gambling websites. Earlier in the form of promotion scams were spread among users with the name of exchanges. Now the trend has moved towards the gambling industry. IT is good to be careful with new gambling websites, because we've got lot of trusted websites with unique games. Whenever getting onto a game know about winning probability, the tricks to win and the strategies that help with lowering the loss.