It’s a well known fact that simple, short headlines garner the most attention and memorability in out of home. But, there are always exceptions to the rule. A long message flips that rule on its head, which can lead to a greater response.
If the concept is to be outlandishly long, you’d better have something interesting to say. It’s also very important that the rest of your design is minimal as well.
Location is also key for these types of messages. High foot traffic, low speeds, and high congestion all make this concept viable.
Here are a few unique examples of billboards that break the simple rule.