I had adsense on this web site for several month. The impressions, ctr and CPM are normally very consistant. In the last two days, Impressions and CTRs were normal. But on Saturday, CPM hit all time low(about 25% of normal) and on sunday it hit all time high( about 400% of normal). Is this normal? Any idea why?
That's just AdSense. I don't worry about it much anymore, so long as what I get paid overall is worth running the ads.