Just as with most events, the instant they end the number of online players
plummets. My suggestion is for their to be more "bonus'" sporatically, maybe even
randomly, so as to help keep the number of players on at any given time higher.

Instead of having an entire weekend event of Xp boost/Item drop, Xp/Item drops
could be for 2-4 hrs multiple times randomly, and perhaps unannounced, throughout
the month.
Or maybe the "coffee card" system could be applied where you get double xp or an
xp bonus for "X" amount of games in a row or maybe even for wins in a row, this
would surely make for better gameplay and reduce in-battle retreating. Game
crashes would get in the way? Don't they already?

Not knowing when a bonus WILL happen is better than knowing that a bonus WONT
happen.

I dont know how technically possible this is, to have boosts be determined on an
individual basis, but it shouldnt be too far off since wins can be counted for events.

Thoughts/additional Ideas/forseen problems?
Dont forget to Rec!