Need some ideas and input.

[Bottle4]

Off-topic mostly, but still, how about there's an login reward system like this:

Like replace the points, zombies, guns & such with something else, and the 4 empty squares will be ment for a daily roulette, which gives you 1 of the 4 items that have appeared.
You can replace them with a random gun from a certain tier, a certain type of gun from a random tier, uniques - whatever you think of!