Nope.
If you havent set up anything in advance to work out where clicks happpen, you can't find out afterwards.
:(

If you haven't installed some clicktracking mechanism, probably the best method would be:

[adwords.google.com...]

Check the keywords for your website or pages in question, and then check the "estimated costs and rankings" from the pulldown (mine is german, so probably the text is different).
Enter 20 as CPC (> 3 times of your share) and sort the result descending.

When you're finished sticky me the keyword :^)

even if you found out which ad it was, there is no guarantee that you'll get another big click like that.

i think that the system works to give the advertiser an average, so there will be some really small clicks to counteract the big one.

Hopefully you setup channels for all your pages.

If not, then you're out of luck. Setting up channels now will help you going forward, but not looking back.

I have about 500 pages so I can't set channels up on all of them.
How can I install a clicktracking mechanism?

thanks :)

If you know it was just a bit past midnight, you might be able to look at your web logs and make an educated guess. If your traffic is low enough, eliminating the robots may only leave 2-3 visitors who were around at that time. Scan through the last page each of them hit, go see what the ad lineup looks like there, and you might be able to make an educated guess about what advertiser it was.

This is one reason I keep a percentage of channels for URL channels. Even just slicing up my stats via a dozen or so URL channels is often enough, when combined with web logs, to isolate where an unusually high-paying click probably came from.

I had noticed a few days ago in the very early morning hours that the numbers seemed a bit high already... checking through my channels I found one channel with a single click valued at nearly $9. Now, for a site that averages $0.07 clicks... this was amazing. :-)

I found one channel with a single click valued at nearly $9

details? :)

I am a firm believer that the high clicks are conversions for the advertiser.
I have a site that deals with a niche where nothing is purchased, just leads. Most times my clicks are pretty cheap, but I do get huge clicks every once in a while. I think this is when the user converted for the advertiser.

I am a firm believer that the high clicks are conversions for the advertiser.

Interesting idea. That would mean you only get a shot at those when your click sends the visitor to one of the (I'm guessing) tiny percentage of AdWords advertisers who participate in Google's conversion tracking.

If this were true, I would think I would see strong AdWords folklore claiming that enlisting in Google conversion tracking typically lowers your cost per click. I do not recall encountering this belief at all on the AdWords side, let alone it being a widespread belief.

To Do: Try to identify which (if any!) of my advertisers are using Google conversion tracking, and then see if they correlate with higher-paying clicks.