Because, we've all agreed on wanting these, and would help boost activity by SO much for PL.
I don't see why Developers haven't implemented such great ideas suggested so many times, but I'm just summing them up once again.

1. Offline Messaging Feature-> Mailbox
-Just send a message to anyone offline. I have found this in EVERY SINGLE MMORPG I have played before PL.
Seriously needs hands down.

2. Microphones/Server Messaging
-The stuff developers have. You can buy with gold or Platinum. Only one-time use. Can be used once very ten minutes to reduce spam. There is a report button for any inappropriate messages.
Why this could be a great addition?
+Allows people to find farming parties WAY faster.
+Allows people to ask questions.
+Allows people to ask about glitches.
+Allows people to ask to sell/buy anything that is currently not on CS.

3. Fishing
-Best way to waste time IMO.
+Well, not really that important but so fun..... please..

4. Super-Mega Skill
I've seen almost 99% of the other games I have played have a special end-game skill that costs a lot of mana or has a huge cooldown and basically does massive damage. I think this would help with clearing more high level dungeons when you are not using an elixir.

5. Longer-lasting buffs in PvE
Would be helpful. Only applies to PvE

6. Instant iPhone Alert/Notification when CS sales have been completed
-Lets life be simple

7. More tradeable dropping vanities like SL
-Because we all need more style in this game. Also because seeing 99% of the mages have full crafted lilith with Mount Fang Armor and SoH shield/Platinum shield is getting boring.

8. New skills
-Because spamming 1,500 Crit Heart Drains without an elixir is not OP enough in a dungeon

9. More emotes
-Because we all want to be able to /die like Justg

10. More storyline
-Because I dunno what happened to the Elf Queen after Fathom Crypt

11. Combo elixir that does not include XP and is discounted
-Because level 66s don't need XP at all

12. Passive Skills/Guild Passive Skills
-Because PL should become similar to DL

13. A more advanced tutorial
-Because at level 65, randumbs do the following:
+Fail at tanking as a bear and scatter
+Fail to deal damage correctly and wait for Blast Shot to cooldown and spam that along with AUTOAUTOAUTO mash
+Fail to heal and revive or do not understand the words Revive in English

14. Needs updated PvP maps
-Because Sewers, Nuri's Hallows and Mount Fang are feeling neglected

15. A higher drop rate for Shadow Caves to encourage farming
-Because it's empty 99% of the time and doesn't drop anything but whites and trash after 50 runs or so

16. Needs more developer celebrity promotion events
-Because we get bored watching not-level 100 players walk around or turn into droids

I only want the top few the most though;/