The PageRank Google assigns your pages is one of your most valuable assets as an online publisher. Your SEO success on Google is dependent upon earning and maintaining PageRank.
In every sense of the word, doing so is a balancing act. Hoarding your PageRank is not good; not providing any links to other websites can be viewed as an SEO sin and it's difficult to get other websites to link to yours when you don't link out, in turn making it more difficult to earn PageRank in the first place.
At the same time, providing too many links can be a bad thing too - under certain circumstances. While the concept of 'PageRank leak' - the idea that you can potentially 'dilute' your PageRank by linking out too much - has been widely debated for years, there's no doubt that good linking practices are important to maintaining PageRank.
Linking to third party websites that Google thinks are 'spammy' can harm you. As Google itself advises, "avoid links to web spammers or 'bad neighborhoods' on the web, as your own ranking may be affected adversely by those links."
This is where using the 'nofollow' attribute on outbound links can be a valuable SEO tool.
As Matt Cutts of Google has explained in the past:
"The rel='nofollow' attribute is an easy way for a website to tell search engines that the website can’t or doesn’t want to vouch for a link...Nofollow is recommended anywhere that links can’t be vouched for."
In short, using the 'nofollow' attribute is one of the most effective ways of ensuring that your outbound linking doesn't harm your website's SEO.
Here are some simple and easy-to-implement tips for using 'nofollow':
- If you have user-generated content on your website, have your application automatically apply 'nofollow' to every link supplied by users in comments, profiles, blog posts, wikis, etc. Doing so will not only protect your website from the ill-effects of content users might submit containing links to websites in bad neighborhoods, it will also discourage spammers from targeting your website in the first place because they know that 'nofollow' neutralizes any SEO benefits they might have received from their shady activities.
- When linking to third party websites, add 'nofollow' to those that you're not so familiar with or that have other content you're not so sure about. In other words, consider every link you give to be a 'recommendation' and recognize that just like in real life, recommendations come with varying levels of enthusiasm.
- If you purchase links, consider requesting that 'nofollow' attributes be added to them. In a previous post, I discussed Google's stance on paid links. Google recommends that paid links include 'nofollow'. If you don't want to take any risks, this is probably a recommendation worth heeding.
An effective SEO strategy is not only dependent upon boosting your ranking but maintaining it and protecting it.
The 'nofollow' attribute is a simple, easy-to-implement way to help your SEO efforts and protect against penalties. It should be included in your SEO best practices.