social activity signals what is authoritative and good?

Technology Review | This ambitious project gets much of its information from the simple "Like" button, a thumbs-up logo that adorns many Web pages and invites visitors to signal their appreciation for something—a news story, a recipe, a photo—with a click. Taylor created the concept in 2007 at FriendFeed, a social network that he cofounded, which was acquired by Facebook in 2009. Back then, the button was just a way to encourage people to express their interests, but in combination with Facebook's user base of nearly 600 million people, it is becoming a potent data-collecting tool. The code behind the Like button is available to any site that wants to add it to its pages. If a user is logged in to Facebook and clicks the Like button anywhere on the Web, the link is shared with that person's Facebook friends. Simultaneously, that thumbs-up vote is fed into Taylor's Web-wide index.

That's how the Wall Street Journal highlights articles that a person's friends enjoyed on its site. This is what lets Microsoft's Bing search engine promote pages liked by a person's friends. And it's how Pandora creates playlists based on songs or bands a person has appreciated on other sites.

This method of figuring out connections between pieces of content is fundamentally different from the one that has ruled for a decade. Google mathematically indexes the Web by scanning the hyperlinks between pages. Pages with many links from other sites rise to the top of search results on the assumption that such pages must be relatively useful or interesting. The social index isn't going to be a complete replacement for Google, but for many types of activity—such as finding products, entertainment, or things to read—the new system's personal touch could make it more useful.

Google itself acknowledges this: it recently rolled out a near-clone of the Like button, which it calls "+1." It lets people signify for their friends which search results or Web pages they've found useful. Google is also using Twitter activity to augment its index. If you have connected your Twitter and Google accounts, Web links that your friends have shared on Twitter may come up higher in Google search results.

Another advantage of a social index is that it could be less vulnerable to manipulation: inflating Google rankings by creating extra links to a site is big business, but buying enough Facebook likes to make a difference is nearly impossible, says Chris Dixon, cofounder of Hunch, a Web startup that combines its own recommendation technology with tools from Facebook and Twitter. "Social activity provides a really authentic signal of what is authoritative and good," says Dixon. That's why Hunch and other services, including an entertainment recommendation site called GetGlue, are building their own social indexes, asking people to record their positive feelings about content from all over the Web. If you're browsing for something on Amazon, a box from GetGlue can pop up to tell you which of your friends have liked that item.

A social index will be of less use to people who don't have many online connections. And even Facebook's map covers just a small fraction of the Web for now. But about 10,000 additional websites connect themselves to Facebook every day.