This week is going to be Ambient Week on Scamp.

I hope it will be fun.

Let's start off by asking the most obvious question - what makes an Ambient ad good?

Mostly it's the same things that make any ad good: clever, funny, relevant, well-branded, powerful sales message etc.

But there are certain characteristics which the Ambient medium offers that no other medium can. And a truly great Ambient ad exploits them. I would suggest these characteristics are Disruption, Provocation, and Super-relevance.

Disruption. Much more so than a press ad, an Ambient ad can be right in your face. A Swedish coffee brand that had the tagline 'for unexpected visitors' built a submarine bursting out of the middle of a city square. And several religious organisations have used inflatable churches - if people won't go to church, let's stick the church by their office, or at the beach.

Provocation. The fact that an Ambient execution is 'real' - i.e. not just a picture of a thing, like on TV, but the actual thing itself - makes it more visceral. This means that Ambient work has a greater power to shock and awe. And at its best, it is wonderfully provocative.

And finally, Super-Relevance. Because an Ambient ad is situated in the real environment, it can be used in a location-specific way, thus giving it a kind of 'super-relevance' that other media can never quite achieve.

This was the first Ambient ad I ever came across - it was given to us as an example in college. And it's still one of my favourites.

The message is tied in perfectly to its physical location.

So those are three examples, I could have picked hundreds more. But do let me know what you think of them, and whether my criteria are the right ones, or if there are other criteria for judging Ambient you feel would be more appropriate.

And keep your own submissions coming in, to simon dot veksner at bbh dot co dot uk. They'll be featured soon.