Best way to 'nofollow' iframe banners ?

[mike2010]

I'm getting conflicting info on how to 'nofollow' iframe banners...so our PR doesn't bleed onto them.

I'm reading here

[productforums.google.com...]

that adding <iframe rel="nofollow" has no effect on outbound links ?

Basically I want to nofollow all my affiliate links....as most of them use 'iframes' these days.

[phranque]

you could use robots.txt to exclude the iframed document from crawling.

[mike2010]

#1 technically speaking, should an <iframe rel="nofollow" do the trick or no ?

#2 any assistance using robots.txt to exclude this particular iframe banner is appreciated. Just to give me an idea , so I could do the same with the others. I never knew you could block them through robots.txt Maybe ur just talking about the URL and not the whole iframe code? anyway, code below :

<iframe width="300" scrolling="no" height="250" frameborder="0" src="http://ads.mysite.com/ads/juggcash_inserts/300x250_1_0_lp.php?nats=NDg0MDYwOjM6NDE" allowtransparency="true" marginheight="0" marginwidth="0" name="" rel="nofollow"> </iframe>

[mike2010]

something else I also thought of after submitting that...

Is that Robots.txt kind of works differently than rel="nofollow" i would think.

PR might still be able to leak onto the external link if it's just Robots.txt'd.

rel="nofollow" specifically tells google "i don't want PR leaking onto this external link".

[phranque]

PR might still be able to leak onto the external link if it's just Robots.txt'd.

iframes don't pass PR - only anchor elements (and if used properly link rel canonical elements)
that's because an iframe isn't considered a link between web resources.

#1 technically speaking, should an <iframe rel="nofollow" do the trick or no ?

i'm guessing the rel nofollow on an iframe won't validate but it's more useless and irrelevant than harmful.

#2 any assistance using robots.txt to exclude this particular iframe banner is appreciated. Just to give me an idea , so I could do the same with the others. I never knew you could block them through robots.txt Maybe ur just talking about the URL and not the whole iframe code? anyway, code below : <iframe width="300" scrolling="no" height="250" frameborder="0" src="http://ads.mysite.com/ads/juggcash_inserts/300x250_1_0_lp.php?nats=NDg0MDYwOjM6NDE" allowtransparency="true" marginheight="0" marginwidth="0" name="" rel="nofollow"> </iframe>

making some assumptions about your url structure - i would suggest blocking any access by googlebot to the ads.example.com hostname or at least the ads subirectory.

the robots exclusion protocol is pretty simple:

The Web Robots Pages:
http://www.robotstxt.org/robotstxt.html [robotstxt.org]

Robots.txt Specifications - Webmasters — Google Developers:
http://developers.google.com/webmasters/control-crawl-index/docs/robots_txt [developers.google.com]

Block or remove pages using a robots.txt file - Webmaster Tools Help:
http://support.google.com/webmasters/bin/answer.py?hl=en&answer=156449 [support.google.com]


note that robots.txt can and should exclude googlebot from crawling the (iframed) resource but G search may index the url without crawling the content...

[mike2010]

thx dude, yea I kinda forgot that we can't robots.txt external files...so i'd have to iframe it locally first, and then robots.txt those files. (directory)

I did 'not' know that iframes don't pass PR at all though. example if my iframe had <iframe=src="http://ads.externalwebsite.com

I would always feel some PR would leak. But i'm guessing your saying no, so i'll believe it.

[Dot_Media]

According to a test Michael Martinez did iframes are now leaking link juice. [seroundtable.com...]

Best bet is to create a local page, noindex, nofollow it with robots meta tag and substitute that page in for the video URL.

[phranque]

i would assume the flow of link juice is from the url of the iframe rather than the url of the page containing the iframe.
i'm not sure how much actual "leaking" is happening.