Ha unfortunately they are for real!  I have to confess that I've never seen this done before, and it immediately alerts my 'dodgy' sensor!

Good point regarding doorway pages.  They are mini-sites with around 8 pages of their own, which then link to the framed site from the nav and the odd text link.  However each of the mini sites has duplicated the same content with the location name changed wherever it appears.  I assume therefore that you'd advise against linking to the main site?

The fact that the site has been framed raises a question if indeed Google does punish this as duplicate content:

If I were a spiteful black-hatter, could I not just frame a competitors site on loads of different domains and harm the original site's SERPs?  I guess in the same way I could do that anyway by copying all the content, so there is a real problem with measuring original/duplicate content.

Something I have not come across before, but hope others here are able offer advice based on experience:

A client has independently created a series of mini-sites, aimed at targeting specific locations.  The tactic has worked very well and they have achieved a large amount of well targeted traffic as a result.

Each mini-site is different but then in the nav, if you want to view prices or go to the booking page, that then links to what at first appears to be their main site.

However, you then notice that the URL is actually situated on the mini-site.  What they have done is 'framed' the main site so that it appears exactly the same even when navigating through this exact replica site.

Checking the code, there is almost nothing there - in fact there is actually no content at all.  Below the head, there is a piece of code:

  <frameset rows="*" framespacing=0 frameborder=0>
    <frame src="[http://www.example.com](view-source:http://www.yellowskips.com/)" frameborder=0 marginwidth=0 marginheight=0>

<noframes>Your browser does not support frames. Click [here](http://www.example.com) to view.noframes>

frameset>

Given that main site content does not appear to show in the source code, do we have an issue with duplicate content?  This issue is that these 'referrals' are showing in Analytics, despite the fact that the code does not appear in the source, which is slightly confusing for me.

They have done this without consultation and I'm very concerned that this could potentially be creating duplicate content of their ENTIRE main site on dozens of mini-sites.

I should also add that there are no links to the mini-sites from the main site, so if you guys advise that this is creating duplicate content, I would not be worried about creating a link-wheel if I advise them to link directly to the main site rather than the framed pages.

Thanks!