[_Kila_]

With 1 hour ticks, a person who has never seen the game before will sign up, click a few things (cons, research etc) and then get bored because nothing is happening and forget all about PA.
Two options:
Run the FB version with fast ticks (1-5mins, maybe even 10)
Let people spend their protection ticks instantly if they wish (similar to light's idea) and then play with 1 hour ticks. A person is far more likely to check back if they've sent an attack out.