A while ago, I compared the numbers for some of the big German websites and portals as measured by Google’s AdPlanner with the results published by the AGOF or Arbeitsgemeinschaft Online Forschung (Study Group Online Research).
Now it’s been one month and I did a short comparison of last month’s Google numbers with this month’s. The result is pretty impressive: almost every page did lose unique visitors in the last four weeks:
Mozilla did experience the greatest loss. I am not sure whether this is a measurement error due to the early release of Google’s application or a real downfall. Perhaps their all-time high on Firefox download day has something to do with this? But a look at the graph Google’s AdPlanner draws for German visitors to Mozilla.com does not suggest any dramatic drop: