These days, it’s sometimes easy to forget that human response to stimuli doesn’t change just because media changes. I thought about that when reading a recent story in MediaPost about the surge of the outdoor advertising business. Over the next four years, it’s expected to grow an average of 13% per year, more than any other conventional media.

The reason? People are more mobile these days. We carry our technology with us and we’re never out of touch, which permits us to be on the road more than ever before. When we’re mobile, we see things like billboards.

And there is technology innovation going on there as well. While passing through New Jersey recently I saw some video billboards that were truly stunning in their clarity and color.

Apple certain he understands the value of this 100-year-old medium. The company spends lavishly on outdoor advertising for its iPods. I suppose it reasons that a lot of target customers can be found standing at bus stops. Good call.