Google’s Matt Cutts recently downplayed the significance of social signals in search, compared to links. Search Marketing Expo uploaded a new video to YouTube, featuring a discussion between Cutts and moderator Danny Sullivan, in which he talks about the notion that social signals have replaced links. In short, while social signals may gain power in time, links are still pretty important.

“If you look at the library of congress, they say they have 151.4 million items,” says Cutts. “That’s roughly 34 million books, and if you convert that to just pure text like OCR, that’s something like ten terabytes. The web capture team at the library of congress says they have 235 terabytes. Now everybody in this room probably ought to be saying to themselves: 235 terabytes for the largest library in the world is not that much data. YouTube gets 72 hours of video uploaded every minute. So the web is the largest source of data we’ve ever seen before.”

“There’s more data being generated on the web, compared to any other source of data around the web, and I think, the fact is, a lot of people think, ‘Links are dying,’ or ‘Links are not a democracy,’ or ‘It’s impossible to get links that aren’t nofollow,’ or whatever,” says Cutts. “And the fact is, that’s a little bit of a bubble in my opinion, in the SEO industry, because if you look at the actual percentage of Nofollow links on the web, it’s a single digit percentage. In fact, it’s a pretty small single digit percentage. So there’s this perception that, ‘Yes, everything will go social,’ or ‘Links are completely obsolete,’ and I think it’s premature to reach that conclusion.”

“I don’t doubt that in ten years, things will be more social, and those will be more powerful signals, but I wouldn’t write the epitaph for links quite yet,” he adds.

You would think that social signals are pretty damn important, looking at Google’s results on any given day, if you’re using Search Plus Your World (and there’s a good chance you are, as it’s the default experience for signed in users). How often have you seen results appear simply because someone you’re connected to through Google+ has +1’d something?

I don’t necessarily think social is the best indicator of relevance, as I’ve discussed in the past, but I do believe they can carry a lot of weight, and perhaps more importantly, will help you diversify your traffic sources, and not have to depend on the search giant for so much of your traffic.