Any SEO problems with Virtual Sites?

I would also like to know about this.

i have several virtual sites running. The base site with the most data is www.dance-ottawa.com. But I have others such as www.dance-toronto.com. They all show pretty much the same data, just arranged in different ways.

dance-ottawa ranks very high in google when you enter appropriate searches, but the other sites do not seem to be listed by google at all. Im not sure how google decides which site to list.

Thanks dpatte for your reply after even though the issue was posted way back.

Have you taken any action in a , adding a "noindex" tag in the dance-toronto domain, or anything like that?

-Patrik

no - did nothing special such as noindex. I did notice today that some pages are indexed several times. Of course each has a different page header and url.
Im thinking now google may list the primary site, with the most links to the main page, and maybe it's only listing the other sites' pages if they are targets of links. People would be quite likely to link to pages in my sites other than the front.

It's a widespread rumor that duplicate content is punished by Google but this is normally not so (see http://support.google.com/webmasters/bin/answer.py?hl=en&answer=66359, where it is also stated that "In the rare cases in which Google perceives that duplicate content may be shown with intent to manipulate our rankings and deceive our users, we'll also make appropriate adjustments in the indexing and ranking of the sites involved.").

At any rate, you can and should use canonical URLs (Nodewords on D6, Metatags on D7) to ensure that, even if you have duplicate content, you tell the search engines what URL you want to see it listed under. That will take care of any problems, will help Google and it will gladly use whatever you supply. The module does absolutely no harm in this process.

Great input. Thanks djg_tram!

Tidying up - seems to be fixed