After attempting to celebrate the Ambient medium a little, it's time to list my three 'Bugbears of Ambient'.
There's a nice book called Guerrilla Advertising by Gavin Lucas and Mike Dorrian that has a great selection of Ambient work. But you know what that book should really be called? "Photos Taken By Creatives". Too many Ambient ads are scams. They're not done for a real Client. They're whacked into place by the creative team, snap, then removed. There are plenty of award-winning Ambient pieces whose media lifespan was less than 2 minutes. Example:
Too many Ambient pieces only work as a photo! They only work because the photo is taken from exactly the right angle. In real life, they wouldn't work. Unless you happened to be standing exactly where the photographer was.
Clients never buy it.