If you are an AdSense publisher and have logged into your account today, you will notice a new tab on the far right with the label "Site Diagnostics". This is a new feature that allows you to view detailed diagnostic information about the pages Google crawls to display relevant ads. They began to beta test this feature back in May with a select group of users (I was not one of them) but have now released it to all AdSense publishers.

What is its purpose? It will show you URLs that Google was not able to crawl as well as provide the reason why it was blocked, the last crawl attempt and the number of times it has failed. How is this beneficial? Google crawls pages so it can determine their subject matter in in turn deliver relevant ads. If they are unable to crawl a page for some reason or another, they may not be able to deliver the most relevant ads which could produce lower click-thru rates. In other words as an AdSense publisher, your earnings may decline.

Some of the reasons why Google may not be able to crawl your page are as follows: your robots.txt file may be disallowing access to page, the server may have been down when they attempted to crawl, the page is password protected, etc., etc.

I do not show any blocked pages in my account so cannot evaluate any data as there is none. Maybe in this case no news is good news for me?