OptiRex at Search Engine Watch Forums posted Just How Much Do You Trust Google/Adsense Stats? Read on... OptiRex says he has a hundred plus sites with AdSense on them and tracks all the data very carefully. Yesterday he said, he "noticed a substantial discrepancy within my Adsense reported figures/earnings." He explains that until the 12th of September the statistics of the custom compared to channels have been only off by a few cents. But now the discrepancy is much larger.
Forum discussion at Search Engine Watch Forums.
Update, AdSense is not crazy. "Relax everyone...Google's not filching from me." See thread for more...
