With no frontline mode, people playing this game think it's just a classic deathmatch shooter with a WW1 setting, and don't want to buy it. But if the frontline mode is available, people will see that it's a great game with interesting mechanics, and will want to buy it. Also, most of the people playing it now don't plan to buy it, because if they did they would have already bought it. So making the frontline mode available only for users who paid the game don't make people buy the game more, they are just more disappointed. PS: Please vote+ so they can see it.