Right now game is not very rewarding the prolonged game. Sure, you can say PvP, but apart from rare fights or organised OP there is no real things to do with our population. From update to update you see not much people logged in, because there is no goal. Some can say its good because you can do whatever you want - I agree with that, total freedom also mean you can get bored in no time. Here are my ideas to increase incentives for at least log in and play for hour every day.

Login tribute
This is quite popular trend in mmos, giving things just for login every day. Since we dont have mail with attachments, rewards can be thrown into gogus. A random gift, from tradeskill lube, ammo to parts and consumables would be nice. I'd like to see constant chain of rewards with milestone bigger rewards (rare part, ultimas, slot enhancers, etc) than chain that reset if you dont log each day.

Daily missions
The thing I really hate, but I understand why they exist. Single mission that can be completed once each day, either its killing certain mob or boss, craft or recycle amount of items to kill X players. Rewards: random thing + bigger chunk of exp and credits.

Daily rewards for holding OPs and War zones
Give OP and War zones some certain thing that can be collected every day. This will also give more incentives to hold as much OPs you can. Best if there is some rng involved, for example cst mod with randomizable stats that need recycling with special lube acquired only this way.

Player defended villages
Can be hard to introduce with level of NC mob AI, but I think it would be beneficial. Idea here is giving something like OP, but for PvE - a simple village that is raided by mobs each couple of hours. If waves of enemies are repelled - all players that contributed in defence get some rewards. Rewards and amount of mobs depend on amount of players in the zone.