Nope. Can't confirm a "blip" from my stats (one major channel/topic/theme). All metrics within their tight estimatess. The four days following June 7th were all up in terms of 7 day moving average, and 30 day moving average.

I had the biggest belly flop on June 8th, a serious "glitch" day, and also unusually low days on 11th and 15th.

Impressions and eCPM both turned south on that day over 10 major channels I track. (Each channel represents a different niche; all the niches fit under a healthcare theme.)

Since imps are pretty much a factor of traffic, I am figuring the Goog serp updates that are being discussed in the Search forum have given me a downward bump. But why would eCPM change also? That's got me scratching my head.

Well, you could call it a glitch, and pretend you've explained something OR....

...with serp updates it's possible that your traffic volume may remain the same, but that the tendency for the "new traffic" will be to click less, which could affect your ecpm. In other words, the characteristics of your visitors changed.

Or, google takes into account how the visitor/clicker got to your site (ie. what keyword phrase) and factors that into your final click payment. SO, as your serps change, so does your ecpm.

Both are plausible, even likely possibilities. Neither is provable.

But why would eCPM change also?

Apart from June 7th being a Saturday and at least on my sites (YMMV) it's almost a free for all on weekends lol :o, I think a change in SERPs can definitely impact eCPM. The reasons why people visit are in the details of the keywords they're using to find your site.

Did you lose positions on popular keywords? Or was there a shift in the phrases they are using to find the site? There's a good thread in supporters by incredibill about how there's seemingly a shift in the amount of keywords used to query search engines with, notably a decline in one and two word phrases.

The 7th was the day of the last maintenance, whatever that's worth. I had a pretty bad 8th and 15th, but in between it wasn't too bad.

from 7th to 14th my ecpm was bad and on 15th it was in normal and on 16th again to a bad status. i can't understand the reason. totally connfusing.

June's been a true roller coaster. One day really high, next day really low. Today is one of them low days.

MB,
I think you are on to something. It's not plausable that I lost rank (equally?) in the serps for each of 10 niches, but an algo shift could bring in a different mix of visitors, and it makes sense that they would trigger a different interest/click presentation, which -as others suggested--leads to a new eCPM. The new eCPM happens to be, sad to note- lower than the previous 12 month's average.

If that's the case, I'm keeping my fingers crossed that Goog will chew on this for a few more days and then compute the best ad mix, and things will be back to normal.

Thanks for the ideas to everyone.

Yup, read low eCPM on 16th. Traffic, CTR normal - so its earnings per click which has gone down.

(These days are coming a bit too often in the last 2 months...)

Well, interestingly - we had the maintenance on the 7th, and as you recall, the reporting didn't come back right away - took a while to catch up. Now I see a message in my AdWords account that it's going to be down again for some hours on Saturday the 21st (two weeks later) and I'd be willing to be that means AdSense goes down as well too. So maybe something needs more tweaking, or got tweaked too hard. We don't usually have two of these in one month.

June 14 - eCPM, CTR and earnings highest ever.
June 15 - 0 clicks (first time ever) - traffic normal

I don't know what's happening however it's Wednesday and my biggest traffic day of the week and SPLAT, my EPC has dropped 20% in comparison to the last few days.

My AdLinks are the culprit again...just when I thought they had resolved Sunday's diabolical metrics here I go down again, no matter what I do, no matter how much content I add, that damned ceiling keeps getting in my way! </rant>

that damned ceiling keeps getting in my way!

the ceiling does not exist... that's what they keep telling me... but there are bumps on my head!

the ceiling does not exist... that's what they keep telling me...

Really, there is no ceiling. That's clear. But wait! There are those massive concrete walls laid horizontally on the top of a room - what was it called again? ;-)

"My AdLinks are the culprit again"

Something has gone wrong with the adlinks. They are paying 1-2 cents a click..down from 10- 15 cents in my niche. This is causing an eCPM crash...

Waiting for the next 'maintainance'.. or maybe ASA can look into this .. ( I wish! )

I tend to be a daily reader as opposed to posting here but I have to agree that something happened on (and from) the 7th as eCPM has sunk to the point where I’ve seen a 40% revenue loss (not an insignificant sum of money involved either).

I’ve seen this before – as will have most of us who’ve been in Adsense for a while – and its always picked up, but even though I know that this is just another stage to be got through it doesn’t stop it from hurting.

Also, out of interest, CTR from non-US visitors has bottomed out so much that I’ve never seen anything like it. Click prices are good, just a marked decrease in clicks. This is causing me concern as I’ve not seen this before and it happened so very suddenly (almost like a door suddenly shutting).

Very bizarre.

It’s all swings and roundabouts of course. Some will be gaining, others loosing but there’s no doubt which camp I fall in.

I dunno, maybe I have your ad links this month, Green_Grass - I just checked, and I'm averaging 12.7 cents per click for June.

The maintainance is back..

I put in my request here..

[webmasterworld.com...]

Yippie..

Please google don't fix anything is it working perfect since June-7 :D

You watch, us who are having issues will be back saying 'Things have never been better...'(crossed fingers) whilst those doing well come in asking what gives...tis the Google dance, lol.

Earnings/eCPM/imps down isn't the only possibility related to this June 7 date... everything could have gone up. The point is more to the June serps changing our traffic, and the results of that change.