> does Google see the iframe as a part of the website?

Yes, but also as a stand alone page. Any page that can be loaded by a spider will be treated as a stand alone page. However, if the iframe is on another domain, then it is not part of "that website".

example:
If we iframed pubcon right here in this thread, Google would not see that as part of webmasterworld. However, the pubcon page would receive credit for a 'link'.

another exmaple: if the microsoft forum here iframed a page from the yahoo forum here, both pages would be viewed as stand alone and pr would still flow from the ms page to the yahoo page.

Lastly, don't get caught up in JS/Ajax load games as well. There are a lot of different browser tricks you can play with iframes. Make sure that the page you are looking at can actually be loaded by a spider by a direct call to the "framed" page.

OK, thanks, although I'm quite disappointed :) That's because I am going to create my new service mostly on Iframe's and I was hoping Google will be smart enough to see a page full of iframes as one page and index the contents as one.

Thanks again.

If they did, it would lead to massive abuse the way "frames" did in the early 00's.

What was that? This "massive abuse"? How this used to work?

Thanks, Brett, that's useful information. I had assumed it worked that way, and used it to my advantage. For example, I have a bunch of links to social media sites that I want to appear on every page, so I put them in an iframe on the assumption that this would count as one link to the iframed page which has one link to each site, rather than as sitewide links to each site. This also has the advantage of making the links easy to manage, though that could be accomplished just as easily with includes or CMS or whatever.

Does that seem like a sensible use of iframes?

What was that? This "massive abuse"? How this used to work?

In the late '90s early '00s, there was a rampant practice of sites framing other sites. For users this could lead to a frame hell where they would become confused as to what site they were really on.

If Google or other search engines counted iFrame content as part of the main page, this would lead to a type of poor man's site scraping where lazy webmasters would just iFrame other people's content in an effort to trick the search engines into ranking their own sites higher in SERPs.

There is no legitimate reason an iFrame should count as part of the parent document, rather it should instead be counted as a link to the child document, because this is essentially what an iFrame is.

But we can do that (site scraping) easily with a few lines of php code. That's why Google detects duplicate content, isn't it?

A note if you intend iframing for google Base (aka froogle): you have to present the entire site when the iframe link is clicked on or google gets annoyed with you (they say). Not difficult to achieve but some browsers totally screw up if they have iframes turned off (ie anti-exploit turned on).

But we can do that (site scraping) easily with a few lines of php code. That's why Google detects duplicate content, isn't it?

You could, and it happens, but my sense is that Google is finding ways to further reduce the damage scraping (although I won't say it doesn't happen, especially for weaker websites, or websites that are in the process of building)