I've pushed post to the home page as it's a good look at how 301's work great with Google but not so much with Bing and Yahoo (not really at all...at least at first).

Great stuff, with real data and information. Thanks for sharing it @markbitanga!

I would agree that at first neither Y or B do pass any juice at all, in fact many times it takes both engines a more than needed time to even notice them and change the url structure in their listings. As far as Google, it has already been known that they pass somewhere around 80% of the original pages juice.

@WilliamC how did you come up with the 80% number?

I don't have any way of measuring it, but from observations alone, it sure feels like a whole lot more than 80% passed via Google. Almost 100% in fact.

But I would guess it might depend on the type of link and redirect.

For instance, a URL shortened via a service might theoretically pass less juice than a redirect from one page of your own site to another. It wouldn't surprise me if Google was getting more sophisticated that way.

Definitely interesting observations. However, I think there are quite a few questions that naturally arise.

For instance,

- did the content of the pages stay the same?

- Were new pages added, indexed, ranked?

- Did SERP rankings --> CTRs change?

- Were there new incoming links during for the new site? Did the link velocity change due to the brand change?

- Were there any additional marketing campaigns that drew additional awareness to the domain / brand change?

I guess my point is, it's hard to draw too many conclusions without having a base line Control Set that also runs during the same time period with similar conditions.

Still very interesting results! ^_^

I agree with Jill that on observations alone Google seemingly passes nearly 100% of the original. I've also had similar results with Yahoo and Bing taking an exorbitant amount of time to notice new URL's and index them, replacing the older versions. In my experience I'd estimate weeks if not months.

@Jill, that was actually a guesstimate on my part based on what I had seen on a few of our own sites when we ran 301's from them to the parent site. I should have made that more clear.

But 80% really? Were you redirecting URLs to ones that were irrelevant to what was on the original URLs?