I don't think there's any way to get this info.
Usually not public, but I know the most "popular" key terms are discussed. Most popular meaning most click, and probably most money for them:
spyware/pop up blockers
If I had to guess, I would ray any variant of these keywords is definitely the most popular.
I am sure others can build on this list
Anything todo with a class action lawsuit.
Mesothelioma - a rare form of cancer caused by asbestos - is, I believe, one of the most expensive keywords.
I recall reading on a thread here (which I can't find!) of bids at US$50 per click.
[edited by: Syzygy at 3:57 pm (utc) on July 28, 2004]
I think mortgage loan/loan application/mortgage application is also a biggy.
are you an adsense publisher or a journalist?
Hey, everybody, I have a great idea!
I'm going to put together some AdSense sites about keywords that have high bids. It's like a license to print money! I'll tell all my friends and family around the country about it, but warn them NOT to click on the ads, even though any money I get from Google will be spent on their Christmas presents this December.
Then I'll go to the Webmasterworld AdSense forum and talk about what a great program this is, how I'm making more money than I thought I would. And also complain about how the EPC is lower than it was in the past.
Is that a cheeky dig, beren?
I'm new to AdWords, but I found a $100/click three word phrase. And it's not even in the adult or pharm sector. I don't know how rare this is or not, but it certainly surprised me... and made me quickly remove it from my keyword list for my first, newbie-testing-the-waters ad campaign!