This week in the Google Webmaster Help Google Groups thread, Matt Cutts made a “Popular Pick” post on the Appropriate Use of the NoFollow attribute and how Google treats that tag, but does not get much into the heated debate of the moment, NoFollow and paid links.
Here are some highlights from Matt’s explanation:
NoFollow and the Google Link Graph
- The nofollow attribute is just a mechanism that gives webmasters the ability to modify PageRank flow at link-level granularity. Plenty of other mechanisms would also work (e.g. a link through a page that is robot.txt’ed out), but nofollow on individual links is simpler for some folks to use.
- There’s no stigma to using nofollow, even on your own internal links; for Google, nofollow’ed links are dropped out of our link graph; we don’t even use such links for discovery.
- Nofollow as a link attribute causes Google to drop those links out of our link graph. If you have a nofollow link from page A to page B, we won’t crawl via page A’s link to discover page B. Note that we may still find page B via other links around the web, though.
Appropriate Uses of NoFollow
- Login and Sign-In Pages : If you visit that page, you’ll see that the “Sign in” link is nofollow’ed. That’s a great use of the tag: Googlebot isn’t going to know how to sign into expedia.com, so why waste that PageRank on a page that wouldn’t benefit users or convert any new visitors?
- Comments : If you write custom software where you’re worried that people might spam the software with links to, I dunno, Ukrainian porn sites, then you can add nofollow in your software on the links that you think might be spammed. If a spammerhas a choice between your software and some other software that doesn’t use nofollow, your software might not get hit as often by spammers
- Link Advertising : ?
Notice that on the Google Groups post Matt does not bring up text link advertising and the use of NoFollow. Does this mean that his views of using NoFollow for paid links have fizzled?
Of course, Matt feels that paid links should use NoFollow :
Matt Cutts Blog If you sell links, you should mark them with the nofollow tag. Not doing so can affect your reputation in Google.
But remember, this is still coming from Matt’s blog and its disclaimer:
I’m one of several Googlers who answer questions online and sometimes for the press. I usually handle questions about webmasters or SEO, so in those areas I’m more likely to make sense and less likely to say something stupid. If I post something here that you find helpful as you build or manage your web presence, that’s wonderful. But when push comes to shove: This is my personal blog. The views expressed on these pages are mine alone and not those of my employer.
[Thanks Tamar for the reminder on Matt's Post]