Changing from a subdirectory to subdomain questions

[bikedorkseattle]

Hi there,

I run a pretty popular forum and in the last year we have launched a affiliate product engine that has been rather successful. We are looking at redesigning the app in an architecture that would require us to host it in another environment ie in a subdomain.

The big question is how does google treat content that is located in a subdomain versus a subdirectory. Is the pageranking/SEO benefits lost moving to a subdomain?

Matt Cutt's has a blerb about this on his blog and didn't give a clear answer, and even reading through the comments it wasn't entirely clear what the outcome would be.

[mattcutts.com...]

Some have suggested there is a negative effect moving to a subdomain. Any thoughts on this would be appreciated.

Cheers.

[tedster]

Welcome to the forums, bikedorkseattle.

This is almost a perpetual topic of interest - and things have changed over the years. It used to be that there was a significant difference in ranking between using a subdirectory and using a subdomain. However, in recent years the two are approaching quite a similar treatment.

There's no set way to predict the outcome of any change - because too much depends on the particulars of each case. The ranking for any URL is mostly dependent on the way backlinks flow into it. So if the subdomain is sort of isolated, then it doesn't really inherit much punch. The same would be true of a subdirectory that was cut off from the domain's internal link flow.

One thing is certain - changing established URLs is a tricky thing, whether it's to a new subdomain, or to a new directory, or just chagin the file path. URL changes almost always mean a short term drop in rankings, and sometimes that drop can be quite extended.

So I wouldn't suggest hoping that a change to a subdomain will automatically bring some kind of improvement in rankings, because it won't.

[TheMadScientist]

We are looking at redesigning the app in an architecture that would require us to host it in another environment ie in a subdomain.

Hmmmm... If you are on an Apache box and know (or find) someone who's talented and well versed in Mod_Rewrite you should not need to change the URLs at all, even if the new app requires the subdomains to work, because you can serve the information from the subdomains to the equivalent directories on the main site, which eliminates the need for moving anything.

You probably need control of the httpd.conf file and may have to serve them through a Proxy, but you should be able to do it without moving, IMO.

BTW: Welcome to WebmasterWorld!

[bikedorkseattle]

Thanks for the warm welcome and the useful information! I have to be honest my forte is not mod_rewrite or server configurations but I have someone who is. I'll be certain to report back on the results of this.

Cheers