1v1 game mode to win a skin from the other player
Both players put up a skin they poses and then they duel for it in a 1v1 game.
For example i create a game in this mode and show other players which skin im putting up. The other players sees me in a list and if they are interested in the skin they put up a counter offer. If I accept this the game is on.
This way Riot dont miss out any money, you can gamble with a skin you dont like anymore, you can get a new skin for a new champion.
So win win win and a little lose is you lose your duel ;)