Advantages & Disadvantages of Billboard advertising

Outdoor/Billboard Advertising Advantages
Big, splashy messages attract attention. Using this medium you must be short and to the point!
Your ad has impact. Technology is allowing for more and more innovations like talking, moving, smoking, changing and twinkling billboards. Hot air balloons, blow-ups, flags, banners and other eye-catching devices are an option, too. You can even hire "rolling billboards" on the back of a truck that drives a route you choose to make sure your billboard is seen by the right audience numerous times.
Your ad reaches lots of people, many of whom see it repeatedly as they travel regular routes.

Outdoor/Billboard Advertising Disadvantages
It's hard to reach a specific audience. You might be able to target a neighborhood, but can't be more specific than that.
Your creativity is inhibited by space limitations.
It's hard to measure its effectiveness.
Your ad may become weathered or vandalized.
Costs can be quite reasonable for a billboard that you want to leave up for a sustained amount of time. However, innovative adaptations can become quite expensive.