Large-Scale Domain Transition

Moving 200.000 pages from one domain to another.

[cleal]

Our company currently owns two domains: one is PR7 and has over 350.000 pages indexed in Google, while the other is PR6 and has about 200.000 pages indexed.

We intend to merge the second domain with the first one, with the lesser possible impact on both SERPs and traffic. Which measures would you take in a situation like this? Is a straight 301 redirection of all pages the way to go? Do you think we would benefit from a gradual transition?

Thanks in advance.

[Quadrille]

If you can be a little 'gradualist', it won't hurt, and may help a little to get a smooth transition with no SE indigestion - but for any serious benefit, you'd probably be talking a spread over months, not weeks or days.

Plus the complication of multiple 301s.

If you have to use multiple 301s anyway (eg not possible to maintain an identical structure on the 'new' site), then it's probably worth the effort.

But whatever you do, it's still a very big change, and there is almost certain to be some damage, even if short term.

Do contact key linkers, and get them to update - maybe to 'section indexes' rather than the domain root. And seek some new powerful links.

Before doing anything, tidy up the 'new' domain, removing deadlinks, orphans and anything that strains the internal navigation - the last thing you need is spidering problems! And check that you can transfer smothly - preferably so that the URLs are identical, asside from the domain name.

If you use sitemaps, nows the time to treble check they are doing their job.

[cleal]

Thank you so much for your help.

Of the 200.000 pages, about 150.000 are going to change significatively (we are going to group the information in a different way, moving from individual concatenated pages to full articles). We are going to produce an approximate mapping from the old URLs to the new ones and set a redirection, but it is not going to be perfect. This is intended mainly for users, so that bookmarks and links are not completely lost. For search engines, I can think of two possible solutions:

a) Prevent access to the old URLs, by means of the robots.txt or the meta noindex tag. This way, we could have a gradual de-indexation of these pages before moving, while the articles could be indexed from scratch in their new URLs.

b) Let the robots see the redirection, although we fear that the pattern might look unnatural (we would have several URLs 301'ed to a single one).

Which solution would you choose? IMHO, a) is probably safer, while b) seems more effective as long as it doesn't get the site penalized. Am I missing any other alternatives?

Thanks in advance.