Make a collective reward for players that are on top of adventure journal, BUT FOR a big amount of players, like the first 10% on top, per month!!!
In this case for example, if the game had 10.000 players in average that played this month, 1000 will receive for example, 10x exp tomes for free. You can do even better and reward the first 5% with even a better gift, like 5X Abrasive Gems, so 500 players will receive this, but don`t give the reward only for a few people on top, or will be like nothing.
The big amount of players just want PVP, or craft things for pvp or infinite tower (world boss content, this things).
Adventure Journal actually is pretty useless without better rewards, because with the NPC in the game, the reward for high levels are pretty weak and Rank means nothing for the people that are not on top 100.
This way players will have a little motivation to don’t stop until the end-game, as well as complete the maps and populate maps that are useless right now.
Another suggestion less important.
The ~Like~ button is another pretty useless thing that just consumed time of development and resources of the game, since players cant do ~Like~ for players inside DGs, only because are in different servers (like if the people of another server would think different, even playing together in DGs. Maybe the most useful thing that Like could provide is on DGs, where players who do their parts (or at least try play like a team), will be marked as an good member in DGs). I now, pretty useless, but at least will be for something more than be stopped like a statue saying ~!!Like me please~