Where did the Audience go?

I have noticed in the past few years that long-practiced methods of communication, such as posters and marquee signs no longer attract the sort of attention to shows that we Theatre people like to see. Why? Have subtle, artistic displays becoming unnoticeable in a world where we are bombarded by images and advertisements everywhere we turn? We still have the reviews in the paper, but we need another way to reach outside our own dynamic. Thoughts?