My friends huge highway billboard only get $3000/year. That is only $8.22/day and that is all day. I can maybe see it for a special event or somthing, but would it really be worth it to you? Projecting a static image is as much work as projecting a movie. Are you going to be able to get your normal rate for such an item? I am not saying that it would not work, but with the weather factor, I would be kinda skeptical. It would not hurt to put it in your advertising materials though.
-- Neil --