Matt Cutts Talks About Rel=Nofollow

Matt Cutts In Favor of Using Rel=Nofollow on Untrusted Links & Talks About How It Should Also be Used for Sites Such as Wikis

• He endorses the use of rel=nofollow tags on links that are posted by users. The idea is to cut down on linkspam.
• For his own blog, he moderates comments to ensure that any comments/links that are posted are validated first. He notes that developers producing software for linkspamming are smart enough to avoid the effort if they know a certain application rel=nofollow's external links - this can be a deterrent for large scale applications.
• He also recommends its use on Wikis since linkspam is an active and growing concern.

He gives a basis evaluation of how to use it effectively with forums (see below).

Originally Posted by Matt Cutts

In an ideal world, nofollow would only be for untrusted links. Let’s take the example of a forum that wants to avoid linking to spam, but the same advice applies to wikis or any other web software. If an off-domain link is made by an anonymous or unauthenticated user, I’d use nofollow on that link. Once a user has done a certain number of posts/edits, or has been around for long enough to build up trust, then those nofollows could be removed and the links could be trusted. Anytime you have a user that you’d trust, there’s no need to use nofollow links.

FYI I'll post a comment in Matt's blog regarding this post to see if it gets published. It might be a bit of an indication of what level of scrutiny Matt places on his spam fighting.

Notes on vBSEO

• vBSEO has several rel=nofollow related features.
• Checkout the vBSEO Demo at http://www.vbseo.com/demo to find out more about all of these options in the vBSEO Control Panel:
  
  Add rel="nofollow" to the Printthread links?
  Add rel="nofollow" to the Showpost links?
  Smart rel="nofollow" for Showpost links?
  
  Internal rel="nofollow"s
  Add rel="nofollow" to ALL Sorting Links
  Add rel="nofollow" to ALL Dynamic Pages
  Add rel="nofollow" to Links pointing TO Member Profiles FROM Postbit
  Add rel="nofollow" to Links pointing TO Member Profiles FROM Forumhome
  
  External rel="nofollow"s
  Add rel="nofollow" to ALL External URLs
  External domains "Whitelist"
  External domains "Blacklist"
• Checkout our vBSEO Conditional Signatures plugin to see one mechanism we have developed to deliver the "fair" application of rel=nofollow to links in user's forum signatures: vBSEO Conditional Signatures - Search Engine Optimization Plugin - vBulletin.org Forum
• vBSEO's CRUs make vBSEO-enabled forums even more attractive to potential linkspammers. The high PageRank that gets distributed to internal thread pages is a big incentive for them. This increases the importance of our rel=nofollow mechanisms.

For Discussion:

• What is your position on the use of rel=nofollow? Some admins content that it is an incentive to keep users posting and building content?
• How do you deal with linkspam? How big of a problem is it for your forum?
• Do you link spam?

Source:
Matt Cutts: Gadgets, Google, and SEO » Quick comment on nofollow

It's been quite a problem for us. We have implemented a rule whereby new memberss HAVE to post in the Introduction forum before they are promoted to full members. We did this by creating a new secondary group called "Full members", and adding a promotion on all users with 1 or more posts. The we made the default Registered Users usergroup only have posting rights in the Introduction forum. It instantly stopped spam.

I talked to Matt in Boston last month about several topics. I need to write up the discussion because it touched on several things that will be of interest to vBulletin/vbseo users. (That's Matt in my avatar with his usual "Choke the Spammer" pose.)

But on the rel nofollow...

Our discussion came around to paid links and Matt indicated that ANY advertiser that buys a plain text link on ANY site should insist upon getting the text link with the nofollow tag.

This topic started as me saying that paid links aren't always to manipulate SERPs. My point was that I may want to buy a text link on some nice website for the traffic that will click thru that link.

He said that buying advertising in fine but ads shouldn't give you a boost in the SERPs. His point was that Google can and will (penalize/ban/apply dampening factor/ignore/whatever) paid links that they interpret as attempts to inflate your rankings. So if you're not trying to manipulate the SERPs, you're not giving up anything by adding the nofollow tag.

But Matt, what if the publisher won't give my text link a nofollow tag?
"Then I wouldn't buy a text link there."

That was the most pointed comment I'd heard from him on the rel nofollow tag.

Take what you want from the comment

That statement by Matt seems ludicrous! How can Google distinguish between a paid text link an any other link? Is he implying that inbound links (without nofollow) can hurt SERP?