This has been a bit of a mystery for me over the last few months. I’ve slowly watched my technorati rating go from about 180 down to where it currently is, sitting snugly at 156 (although it was 159 yesterday). Considering it’s been climbing non-stop since last year, I’ve been a bit confused as to why it’s started to drop.
After doing some research, it appears that technorati has been busy changing things on their backend. Recently, they made it so subdomains no longer count towards main domain scores. This has hurt the rating of quite a few large blogs.
Prior to that change, technorati made it so that the authority rating is measured on a six month sliding scale. What that means is all your links that are over six months old are no longer going to count. Kiss all your links from other people’s blogrolls goodbye. In my case, I had a huge rash of people linking to my crossroads plugin last year, and apparently all those links are expiring. So if you received a whack of links during a certain time period, I’d set a countdown timer and see what happens after 180 days — chances are you can kiss yours goodbye as well.