Word of the day: ambient advertising

I recently came across the use of ambient to refer to advertising in the environment. As in ambient light, it's just there. The advertisers' hope is that such ads are not seen as being projected from a source (like a billboard or TV) toward the potential customer but that they are just there as part of one's environment.

While looking for web references I found the World Wide Words website. This is from its Ambient Advertising page.

… almost any kind of advertising that occurs in some non-standard medium outside the home. Examples are messages on the backs of car park receipts and at the bottom of golf holes, on hanging straps in railway carriages, on the handles of supermarket trolleys, and on the sides of egg cartons …

Ambient advertising contains the seeds of its own destruction … because once the approach is copied and becomes commonplace, it ceases to surprise.
[Guardian, August 1997]

Ambient advertising was in the news most recently when blinking lights were scattered around Boston as part of an advertising campaign. They were at first thought to be terrorist devices. Turner Broadcasting has agreed to pay a fine of $2 million.

It seems to me that what was striking about these ads was not that they were ambient — ambient advertising is ubiquitous these days — but that they didn't look like advertising.