Google Adsense and Blogspot Blogger have been recently make significant changes on the adsense advertisement on blog. In the past, all you need is to identify your adsense publisher ID (called google_ad_client), your adsense slot ID (called google_ad_slot). Now, there is a new identity being added - Google Adsense Host ID (called google_ad_host).

Publisher ID is to identify your account, such that all the click on ads will generate income to your account.

Slot ID is to identify the particular adsense identity, e.g. the channel, the color, the size.

The new Host ID is to identify the blogger host that host the ads. This may due to the fact that many people has many Blogspot account, and in order to obtain Google paycheck every month, different Blogspot account share the same Adsense Publisher ID.

The new code looks something like:

google_ad_client = "pub-1234567890123456";
google_ad_host = "pub-9876543212345678"; (<-- this line is something new)
google_ad_slot = "35678901245";
google_ad_width = 250;
google_ad_height = 250;

Don't be surprise if you didn't see that line when you obtain the code from Adsense. That line will be added by Blogspot after you paste your Adsense code into your blog. It will be added even nif you add the adsense code directly to your template. And this may explain the recent glitch happen at Blogspot.