Welcome to WebmasterWorld Guest from 220.127.116.11
I know if you have banners it will only show an url if you have only one ad in the banner but I believe it shows the url for each ad in a skyscraper.
I was trying to think of the reasoning behined this but could not come up with anything wonderful. After all this could lose Google revenue etc. Any ideas?
The whole idea of AdWords is to provide high-quality ads to readers who want to see them. It just makes sense to give them a little meta data.