1script - 4:53 am on Jan 31, 2013 (gmt 0)
Yup, that's Russian impressions all right - they can explain pretty much all of the spikes I'm seeing so far. What I don't understand though is that it's not just any additional Russian impressions - it's a hell of a lot of BAD impressions at google.ru, the ones that don't convert to clicks. I was paying particular attention to a couple of my sites that have always had traffic from google.ru, so I know that there should be *some* conversions, and yet I'm not seeing any additional traffic from there, despite the incredible increases in the number of reported impressions.
I thought that they may be experimenting with some badly converting new layout or something and took a stroll to google.ru - it does not look or operate any different from .com So, the sudden influx of impressions still looks like a reporting error to me.