Over the last few days have started hearing reports from hundreds of AdSense publishers worldwide who are almost all saying that they're seeing their eCPM paid by Google for AdSense go down by 30-50% starting on or near October 19th.
There's a thread on Webmasterworld on the topic, and the reigning theory is simply a profit grab on the part of the 'Plex. Here are some of the quotes from that thread for those of you who aren't forum dwellers like me:
" I have seen a reduction to the extent of Friday's [Oct 19th] being 50% of the first 15 days of October."
" my eCPM is down by 50%"
"Similar scenario here. Traffic has been healthy and extremely well targeted, yet my October average for Adsense this year is way down."
" I just checked, and we're down 33% for the same days compared with last October, but around 13% of that is because we've taken a good number of pages out of Adsense to try to get our CPM back up."
"my traffic levels and sources are right where they have been for the last six months+ but my earnings have dropped over 50% to levels lower than my worst days in the last six months - and are still trending downwards!"
"eCPM for my biggest earning page is down by 50%."
"Traffic for me is up, AdSense CPM is down big time - this week was 24% lower than last month. I had record setting months recently (earnings and traffic), but things are sliding down. I do not know why."
"This October is awful. I haven't seen it this bad since I started."
" My earnings for October 2007 are 34% below that of October 2006. "
" My eCPM since Friday 19th October, the date many are mentioning, has averaged, the average quoted here, -30%."
"my eCPM is now -65% compared to my year and early October average."
" Our ecpm's have been down by about 30% for the last 10 days or so though traffic has been steady. "
"My eCPM is down ~50% vs. normal levels."
" Earnings are down to 50% yet traffic is up. It has been the worse 3 days for ages. I guess it is time to see what yahoo is offering or am I wasting my time on that one? "
" As a site which has averaged approximately 30,000 daily page views a month for over three years now, with a yearly increase of about 5-10% in traffic, I have seen a marked decrease in eCPM in October, and this site is remarkably consistent otherwise."
" [eCPM] continues to drop to the levels that is unacceptable. Our ecpm is 30% of 1 year average. "
"eCPM is down almost 20%"
" Same here... We saw ECPM drop by a third in the middle of Oct. It had been steady for years. Not sure whats up. "
" ecpm still very low, down 50%"
"same number of visits , same ctr, same number of clicks , but the earnings decreased by 50%"
"I have about a 60% reduction in eCPM now. (It's getting worse.) "
" Things are still down for me. We're not talking a dollar a day, we're talking X,000 per month DOWN. "
"Single large site, 60% ecpm drop, $X,000/mo loss, traffic/costs are growing..."
"One large site, also several thousand monthly loss."
" Several large authority sites, traffic ranges per site 1-2 million users per month. Revenue loss, deep X,000.00 figures per month. BTW all the sites dropped at the same exact time with no change in ctr or traffic and someone at google says we are not smartpriced. So you tell me #*$! happened?"
Googol is certainly eating Pi as if it were an infinite number...