Travelling through Victoria one evening last week at rush hour, I saw this:
It's a real person, relaxing under a sun shade wearing holiday clothes. And the message was "BA's sale is now on." It's not very clever thinking, quite simple in fact: Remind people of what going on holiday is about. But it was highly effective because it really made you stop and think: Mmm yeah, I might check out their sales and see what they have.