Bigger Than At Times Square

The advertising industry is always looking for the next big idea. So here's one that spans more than five acres: London-based Ad-Air Group is placing gigantic flat ads in deserts and farm fields adjacent to airports. Captive airline passengers who glance out the window on takeoff or landing won't be able miss them.

In October, the firm unveiled its first ad, what it calls "the largest advertisement in the world," near Dubai International. CEO Andrew Ward says that the site particularly appealed to the large real-estate company that placed the ad because it's a key spot for catching the attention of people doing business in Europe and Asia. Within weeks, Ward expects to announce two new ads in London and two in Paris, and then ads this summer in Atlanta, Phoenix, Denver, Tokyo and Beijing.

The huge ads, which will cost companies at least $1 million, are low tech and not expensive to produce. They're digitally printed on pieces of PVC mesh that are assembled on frames that sit a few inches above the ground on the site. The most challenging part of the Ad-Air business is finding locations. It's not easy to find open fields close to big cities—and you always have to make sure to keep cows away.