Why would my domain authority drop 2 points in the last week?

[elubes]

My domain authority went from 51 to 49 in the last week. I haven't done any shady link building or really changed anything on the site. It is an ecommerce site so there is new product always added and we also have a full content magazine, so new content is added every monday and tuesday. The only thing that has happened is a press release went out on PRweb about a collaboration we've done.

[UnderRugSwept]

In an effort to update more often, SEOmoz/OSE are crawling fewer URLs. Likely, it's not that something happened to your domain; it's the fact that fewer of your backlinks have actually been detected by Open Site Explorer.

http://www.seomoz.org/blog/july-mozscape-update

FYI: My DA used to be 45 and now it's 41. I noticed that was because OSE wasn't detecting some of my backlinks that I know are still there. My advice would be not to worry too much, especially if your rankings haven't be affected.

[UnderRugSwept]

Coincidentally, today I just came across this page for the first time and I remembered your question.

http://www.seomoz.org/learn-seo/domain-authority

The key takeaway I picked up on:

"We constantly refine this model over time. This means your website's Domain Authority score will often fluxuate. For this reason, it's best to use Domain Authority as a competitive metric against other sites as opposed to a historic measure of your internal SEO efforts."

[elubes]

Thanks! Very helpful!