We do. Our yard haunt is actually a live variety show that runs the week before halloween, complete with dancers and fire spinners. So facebook is our main source of advertisement. Otherwise I would have strangers ringing my doorbell nonstop to ask when the show is.
Although last year I was in the yard tinkering the day before our first show. A car drove by and slowed down to look, as they always do. But then a couple got out of the car and came to talk to me. They were from Texas, I am in Missouri. They were in town visiting relatives and had been at Lowes. They over heard the people in line in front of them talking about our show/yard. And they wanted to come see it for themselves, before they left town to go home.
So even though we intentionally use social media to advertise I REALLY like the grass roots, underground, cult classic, word of mouth advertisement best.