Today I was going through an interview of Matt Cutts at StoneTemple Consulting that was published about 10 days ago. And here this fact about 301 redirect caught my eyes. When we move to our new domain we usually use 301 redirect to seamlessly redirect our users and search engines to our new urls from the old ones. And most of us, the webmasters know that pagerank juice and link popularity will be added by Google from the old domain after some time.
Well, that is still true. But think about this case. Somebody has linked to your old domain url. So first the link juice will be passed to the old domain and as you are using 301 redirect it will be passed to your new domain. But there will be natarul decay of link juice while passing from one link to another. Matt Cutts has confirmed this case. So you will still gain most of the PR but there will be some leakage of link juice. Here is what Matt Cutts had to say about it:
Eric Enge: Let’s say you move from one domain to another and you write yourself a nice little statement that basically instructs the search engine and, any user agent on how to remap from one domain to the other. In a scenario like this, is there some loss in PageRank that can take place simply because the user who originally implemented a link to the site didn’t link to it on the new domain?
Matt Cutts: That’s a good question, and I am not 100 percent sure about the answer. I can certainly see how there could be some loss of PageRank. I am not 100 percent sure whether the crawling and indexing team has implemented that sort of natural PageRank decay, so I will have to go and check on that specific case. (Note: in a follow on email, Matt confirmed that this is in fact the case. There is some loss of PR through a 301).
So be a bit more serious while going for a new domain for your site