europeforvisitors - 12:08 am on Mar 12, 2007 (gmt 0)

My guess is since we don't know the causes for sure and every time a thread like this gets started the "list of causes" get bashed by folks who say "it can't happen" even though it cannot be proven to not be a cause.

Yes, just like the Pope can't be proven to not be gay.

The problem is that rational discussion tends to become lost in threads where angry publishers vent with claims (often presented as fact, despite a lack of suporting evidence) such as:

- Google is cutting AdSense earnings across the board;

- Google is favoring Wikipedia in its search ranking to sell more AdWords;

- Google introduced Quality Scores on the AdWords side simply to make more money (never mind that higher minimums have driven some advertisers away);

- Google is purposely corrupting its search results because bad SERPs encourage users to click on ads;

...and so on, ad infinitum, with Webmaster World looking more like #*$! [site name censored by WW forum software] all the time.

Getting back on topic, I'll refer you back to Sailorjwd's list of possible--or even likely--reasons why some (but only some) Webmaster World members are seeing "an EPC collapse."