Referal links to a page and SEO

How to overcome duplicate content when affiliates are linking to a page

[forcer]

Hey!

We have recently launched a site where users can put links to their blogs with the affiliate code

e.g.

<a href="http://www.mysite.com/join.aspx?friend=bob">join me on mysite</a>

Now my site has multiple versions of join.aspx page indexed in google.

Is there any way how to tell google and other engines to index just one version of the page? I know I can 301 redirect the referal links to the one page, but I don't want to confuse users. I want to keep the url in the address bar the same.

If I redirect the join.aspx?friend=bob to join.aspx just for search engines, is it considered as cloaking?

Any other good way of fixing this problem?

Thanks

[futureX]

i would just disallow join.aspx in robots or add a noindex to the meta tag to stop google from indexing it at all.

[kevsh]

I have had this situation before and the best way seemed to be to disallow index (with parameters only) in robots.txt and to be sure, use custom code on the page to put a META norobots tag, again only if the page is accessed via parameters.

Unfortunately, you will probably lose credit for inbound links but if your biggest concern is duplicate content, that should do it.

[g1smd]

Dynamically put a noindex tag on the page if the URL is not the canonical form. Make sure that the page contains a clickable link to the canonical form so that bots can still get to it.

[marcel]

Wouldn't it be possible to store a cookie on entry and then redirect the visitor to the page without querystring with a 301?

[forcer]

Thanks guys for your suggestions.

I guess there is no perfect solution for that.

Not sure what is worse..

if to have duplicate content indexed or put "no index" meta tag on every variation of the join.aspx page. That means loosing all the SEO benefit from referal links.

I think I will just leave it with duplicate content?

[g1smd]

Put a noindex tag on all non-canonical forms, and make sure that there is a link to the canonical form of the page on the non-canonical form of the page. The bot will still follow that link, even with the noindex tag in place.