the only thing bytro can offer players to stay in a round is gold, maybe after a week all active players get a small amount of gold and so on till the end of the round ????
A small gold amount payable at the conclusion of a game as a 'loyalty' payment would definitely keep more people in a game until conclusion. a weekly even smaller amount if you login each day would see much more activity in games. World of warships and other games already do this successfully.