Canonical tags and GA tracking on premium sub-domain?

[grumbles]

Hello!

I'm launching a premium service on my site that will deliver two fairly distinct user experiences, but with nearly identical page content across the two. I'm thinking of placing the "upgraded" version on a subdomain, e.g. www.mysite.com, premium.mysite.com. Simple enough. I've run into two obstacles, however:

-I don't want the premium site crawled separately, so I'd like to use canonical tags to pull all premium.* back to their www.* parents.

--How different can page content be before canonical tags backfire?

--Is there any other danger in using canonicals across subdomains like this?

-Less importantly: with Google Analytics, if I track against the subdomain my visits will split naturally, and it should generate a second cookie for a new registrant who crosses subdomains. I could also use a visitor-level custom var. Good idea? Bad idea?

Thanks!

-m

[grumbles]

Thanks, guys! Both of your answers are right in line with my suspicions. I think at the end of the day, I'm going to opt for one domain, one URL-set, different wrappers, and canonical tags just in case the crawler ever wriggles its way through the pay wall... which, given callbacks to server-side user data, should be impossible.

Thanks again,

-m

[Dr-Pete]

I think John is right on all counts. I'll just add that, while the canonical tag should work fine, you may want to consider whether it makes sense to index the premium content at all. It really boils down to whether you think people will link to the premium versions, in which case the canonical tag would help consolidate that link-juice.

The other option, of course, would be to roll-out the wrappers/upgrades dynamically and not even have two copies - everyone would see the same URL, but premium members would see it differently. In most cases, I think that would be the best bet for SEO. It also means you're not maintaining two copies (although I'm guess your current set-up is at least partially dynamic).

[john4math]

You should be fine if the main content of the page is very similar.  You can use canonicals across different domains, so different subdomains won't be a problem.  You can use the tool here to check to compare two pages: http://www.webconfs.com/similar-page-checker.php.

With Google Analytics, you can set up multiple profiles to be driven from one GA tracking code.  Just make sure you've set the tracking code to to track one domain with multiple subdomains.  You can create additional profiles with filters on them, so you can have on profile for the www domain, one for the premium subdomain, and one with both.