PageRank Sculpting & Blog Comments

  • 1
  • June 16, 2009
Patrick Altoft

Patrick Altoft

Director of Strategy

PageRank sculpting was quite a straightforward topic until recently – you just needed to add the nofollow tag to links pointing at “useless” pages such as shopping baskets and login forms and your rankings for long tail keywords magically jumped up.

I’ve heard people talking about 70% traffic increases across large websites purely using this method.

Matt Cutts has tried (and failed, in my opinion) to clarify the issue with a new PageRank sculpting post. The comments are excellent, a mixture of people who don’t understand SEO blindly saying “great post” and the usual knowledgeable people actually questioning things.

Here are some quotes that have me confused.

So what happens when you have a page with ten PageRank points and ten outgoing links, and five of those links are nofollowed? Let’s leave aside the decay factor to focus on the core part of the question. Originally, the five links without nofollow would have flowed two points of PageRank each (in essence, the nofollowed links didn’t count toward the denominator when dividing PageRank by the outdegree of the page). More than a year ago, Google changed how the PageRank flows so that the five links without nofollow would flow one point of PageRank each.

That makes sense but I would like to know where the other 5 points went.

There may be a miniscule number of pages (such as links to a shopping cart or to a login page) that I might add nofollow on, just because those pages are different for every user and they aren’t that helpful to show up in search engines. But in general, I wouldn’t recommend PageRank sculpting.

Most intelligent SEO’s only used nofollow on these pages anyway. Is Matt suggesting that this sort of sculpting will still raise the rest of the sites rankings or is it just to remove these useless pages from the index?

Q: If I run a blog and add the nofollow attribute to links left by my commenters, doesn’t that mean less PageRank flows within my site?
A: If you think about it, that’s the way that PageRank worked even before the nofollow attribute.

Q: Okay, but doesn’t this encourage me to link out less? Should I turn off comments on my blog?
A: I wouldn’t recommend closing comments in an attempt to “hoard” your PageRank. In the same way that Google trusts sites less when they link to spammy sites or bad neighborhoods, parts of our system encourage links to good sites.

Surely Matt must understand that a large percentage of the comments left on popular blogs link to spammy neighbourhoods? Some of my posts link to some terrible sites in the comments but I just ignore them because they are nofollowed. I expect the average blog comment link will be on the “spammy” end of the scale rather than the “good” end and therefore will hurt my trust and not help it.

If every comment is going to reduce the PageRank flowing to my other links then surely I need to start being a lot harsher in my comment moderation. Also Matt seems to be implying that Google actually looks at your nofollowed external links and uses the results in calculating your rankings, does this also mean that nofollow links can pass trust to other sites?

Danny Sullivan has summed this up in his comment which has yet to be answered:

Say I have an article on a blog with 5 links in the editorial copy — some of those links leading back to other content within the blog that I hope to do well. Then I get 35 comments on the article, with each comment having a link back to the commenters’ sites. That’s 40 links in all. Let’s say this particular page has $20 in PageRank to spend. Each link gets 50 cents.

With nofollow before the change, I could have (if I were worried about flowing PageRank), kept any of those comments from getting some of my PageRank spend. Nofollow them all, and the 5 remaining links each get $4.

With this change, I can still get the $4 if I simply don’t allow comments. Or I show comments, but I use an iframe, so that the comment actually reside on a different page. In either case, I’m encouraged to reduce the number of links rather than let them be on the page period, nofollow regardless. If I’m worried my page won’t seem “natural” enough to Google without them, maybe I allow 5 comments through and lock them down after that.

Perhaps comment spam is about to become a competitor sabotage technique?