I don't really like the idea of advertising when we're awake and when we're asleep or when we're home/away. Ours are on all the time right now but that was just this past week of excitement at having put them up. It's been gloomy lately so you can see them even when it's daylight (at least a little bit).
But the real reason that they're on all the time is laziness. I vow to go put them on timers tonight! It's better for the bills.
Looking forward to Christmas a little early this year.