Duplicate Content Problem with Google?

Passing a parameter in a URL.

[diamondgrl]

I have a site that has products listed as such:

[example.com...]

Then when the user adds the product to their cart, it is passed as a GET variable as such:

[example.com...]

Now I think Google may be choking on this formulation because it is seeing duplicate content. Still getting referals but not as many and the SERPs are a lot less clean than they used to be. A lot of URL-only listings, for example.

Any thoughts on

a) whether this is a serious problem
b) how best to rectify it?

On the latter, I am thinking I might change everything to POST and then 301 the URLs with the cart variable since whoever is coming to that page must be a search engine or a search engine referal that clearly didn't mean to add something to the cart.

[goodroi]

Any chance of duplicate content is a serious problem. If you are seeing Google showing these variables in their index, you should take steps to block them from Google's spider. Otherwise you might risk your rankings.

[stickyboy]

i have a problem on my site where it looks like it may be a duplicate content problem as I have some pages that appear for www.domainname.com and others which appear with the www.

My host did a DNS change so that all links from domain.com goto www.domainname.com . Is that ok or is a 301 redirect better?

[stickyboy]

anyone?

[jeffwade]

I am having the same problems, but with subdomain, the root of them is common for all and I have been penalized for duplicating code.

I used the remove tool of Google to eliminate all subdomain, today I just received the confirmation email that they have been removed from the index, but nothing has changed, I guess I have to wait for the next update.

[lost in space]

simple, once you pass the variable to the URL also serve up all pages from there forward with the "meta robots" tag set to "noindex,nofollow" and the spiders won't go any further, and it won't effect the users experience at all either.

I'm assuming you're using a language that allows modification of the page text before it is served up (PHP, ASP, CGI, ISAPI, etc).

[stickyboy]

thats not going to work in my case. The problem with my site is that google is seeing some pages with www.domainname.co.uk and others without www. I want to get rid of the non www pages so was told to do a 301 redirect. Only before I did that the host setup a DNS change to the A record so that domainname.co.uk forwards to www.domainname.co.uk

My question is, is that good for google or is a 301 redirect better?

[JuniorOptimizer]

StickyBoy, the 301 re-direct would be better. That's the way most people have it set up, with very few issues.