A WebmasterWorld thread has discussion around one advertiser noticing Google displaying three scores directly under a Google Netherlands ad. Here is a picture of the ad with the scores underneath the ad:
So I began to do some research and it seems someone else saw the score for a different search today as well, on Google.de. Here is a screen capture, but even though the webmaster highlighted the score with the middle ad, I have a feeling the score is associated with the top ad:
Here is another:
So what does the scores mean? - Pscore: 0.00101 - mCPC: 10.0000 - thresh: 0.0001
mCPC, seems logical, the minimum cost-per-click for the ad is $10? The Pscore and thresh, I am not sure about.
It seems like many folks are spotting this in Google's international search engines.