Many online marketers know that one of the keys to search engine optimization success is link building. Some believe using nofollow links is their best option, a topic Google's Matt Cutts brought up in his latest YouTube video on the GoogleWebmasterHelp channel.

Many online marketers know that one of the keys to search engine optimization success is link building. Some believe using nofollow links is their best option, a topic Google's Matt Cutts brought up in his latest YouTube video on the GoogleWebmasterHelp channel.

According to Cutts, a very small percentage of the links on the web are nofollow. In the video, Cutts classifies these as a “very small, single-digit percentage” and notes that despite being around for five years, nofollow links are still the minority.

Cutts says that he doesn't foresee Google penalizing sites for using nofollow links, but he does believe that the way sites use links in the future will continue to grow, focusing more on the validity of the sites they link to.

“I wouldn't be surprised if we continue to see sites grow more nuanced so as people or websites build up trust in particular individuals they might say, 'OK, I'm alright to link to that person,'” he said in the video.

Still, on the Google Webmaster Central website, the search engine lists some reasons sites might want to use nofollow. Backing up Cutts' point, Google says that if a site is unsure of the content from a link, it should use nofollow to discourage spammers.