Over the holiday break we found and fixed a bug that inflated authority counts for certain blogs. The blogs affected were those on domains that also have linked-to sub-domains. The links to the sub-domains were erroneously counting toward the blog authority of the blog on the parent domain. Since Technorati Authority is a calculation of how much attention is being paid to a blog and the posts beneath it, we do not include sub-domains. Sub-domains are treated as separate entitities and often are references to tools, utilities, features, and other non-blog resources.

Examples:

http://chinese.engadget.com
http://desktops.engadget.com
http://hdtv.engadget.com
http://storage.engadget.com

Well, we fixed the bug yesterday. The impact of this change is mostly limited to the Top 100 and the overwhelming majority of the blogosphere is unaffected. Thanks for bearing with us while the Top 100 experiences some turbulence.

We're always thinking about how to improve and develop new meaningful metrics for the blogosphere and we welcome your feedback on these issues.