By Heather Green Josh Schachter is a true techie. Though the 30-year-old New Yorker is a programmer at a financial-services company, in his off hours he writes a blog and works on his own software as a hobby. He attends Foo Camp, the annual retreat run by tech publisher O'Reilly & Associates (hence, Friends of O'Reilly, or Foo) that assembles techies so they can show off their works in progress. When he runs into a problem, Schachter's answer is to cobble together some software to fix it.
Which is exactly what he did a little over two years ago. As Schachter began collecting links he wanted to write about for his blog, he needed a place to store them. At first, he simply pasted them into a file. But when the file became a sprawling mess, Schachter created a software program combined with a Web site that enabled him to tag the links using words he would remember so he could find them later. So when Schachter saw a story about, say, Wi-Fi wireless networking, he would slap a Wi-Fi tag on it and file it away.
"FOUNTAIN OF INTERESTING THINGS." By the end of 2003, Schachter had turned his own creation into a service called del.icio.us that anyone could subscribe to for free. On del.icio.us, people are able to tag any link they choose for easy recall later. That tagged link is stored on every subscriber's personal area on the service -- and it's added to the overall service so that users interested in a specific topic can easily find new links.
So, for instance, if someone tags a link to a story on Iraq, it's added to a list on del.icio.us of other content that also has an Iraq tag. That enables anyone on the service who wants to read about Iraq to find a list of stories that have been tagged, see who tagged each item, and find related tags. More than 60,000 people are now using the service, which describes itself as a "social bookmarks manager." "It's a way to augment your memory and a fountain of interesting things," Schachter explains.
Now, the notion of end users tagging content is reverberating throughout the Web, giving people a new way to think about how information is organized and found online. If it keeps gaining momentum and developing, tagging has the potential to eat away at traditional search. It wouldn't replace search as we know it, but people could turn to tags more over time, displacing time they spend on established search engines.
ADDING CONTEXT. Indeed, such tagging is already being adopted by popular startups, including blog search engine Technorati and photo-sharing service Flickr. It has also caught the imagination of well-respected thinkers online, including Dave Weinberger, a research fellow at Harvard's Berkman Center, and Clay Shirky, an adjunct professor at New York University's graduate Interactive Telecommunications Program, both of whom have written extensively about tags on their blogs. "Del.icio.us is about the most important software launched last year," says Shirky.
So why are people intrigued by tagging? Until now, search engines -- most of which belong to the gang of four: Google (GOOG), Yahoo (YHOO), AOL (TWX), and MSN (MSFT) -- have been the standard Web way to find and organize information. Yet, no matter how many pages they index or how quickly they bring back those results, most search engines can't really put things in context.
These engines make attempts by including the Web page heading that contains the result. But fundamentally, most simply lump together everything having to do with a specific word. For instance, if you look up the words "electronic publishing" on Google, the list of results throw together the lists of electronic publishers, The Journal of Electronic Publishing, and disclaimers on copyright. On del.icio.us, you get a list of links tagged with electronic publishing, but also related tags, such as blogging, journalism, and wiki, which can help you quickly navigate to specific articles.
WEB OF RELATED TAGS. Tagging systems allow people to work together organically to create a structure around issues, blog entries, Web links, or photos. Blogger Thomas Vander Wal coined the word "folksonomy," which combines the words folk and taxonomy, to describe this joint work. It's almost a grassroots Dewey Decimal Classificaton System. The essence: The combined work of people busily tagging content creates another way of making sense of the information floating around on the Internet.
This joint effort, though, is prompting a debate about tagging. Critics argue that tagging could collapse under its own weight because it isn't a standardized system created by professionals. In the free-flowing tagging world, one person might apply the tag "seal" to the animal, while someone else applies it to the musician. Or, as more broad words are used to tag content, such as Iraq or wireless, too much information will be collected to plow through.
Shirky and others maintain that no one company could afford the cost of applying standard tags to everything found on the Web. Only many individuals tagging every day could help structure the vast amount of Net content. And these individuals and early adopting businesses are devising ways to make it easier to find just the right information using tags.
Flickr, for instance, includes a list of related tags. So the generic NYC tag, "Flickr: Photos tagged with NYC," also has related tags including "newyork," "centralpark," "subway manhattan," "brooklyn," "art," "night," "park," "snow," and "newyorkcity," as well as "christo," "thegates," "gates," reflecting interest in artist Christo's massive art installation, The Gates, that's currently in Central Park.
INSPIRATION TO SHARE. "Del.icio.us is less than a year old and spawning novel work like crazy, so predicting that the thing has run out of steam...seems like a fatally premature prediction," Shirky wrote in January about the debate.
Tagging is taking off because it's just so easy, making it simpler and more fun to share with friends or colleagues. On Flickr, people tag their own photos when they load them onto the site, but other people can tag their photos as well. Looking at the list of 150 most popular tags gives a broad idea of which subjects are being snapped the most.
It's not surprising that "wedding" or "NYC" are popular tags, but because the list adjusts with the volume of tags, ones like "tsunami" will become more popular at certain times. Sometimes, people create a tag meant to inspire others to take and share photos, such as "what's in your bag?", which collects photos of the contents of people's computer bags, knapsacks, purses, and such.
WHAT OTHERS ARE UP TO. Consider how tags have given Flickr a major boost. Although it's still in beta, the year-old service is growing about 30% on average each month and now has more than 300,000 users. "When we added tags, it really changed the nature of the way that people were sharing photos," says Caterina Fake, co-founder of Flickr.
Tags also help reveal what's popular on the Internet generally or at particular sites and provide a novel way to navigate through information. For instance, check out the tags index at Technorati. The blog search engine tracks the tags that bloggers give to their posts, photos, or links.
Or at del.icio.us, if someone is keen on a Web site that creates a parody of Christo's The Gates, he or she can tag it. The first person to tag it on del.icio.us used the tag "art." Over 40 people have copied that tag to their own sections, some tagging it as art, but also as "funny," "humor," "Christo," and "thegates." As more people tag it, the Web site floats toward the top of the list of the site's most popular tags. That way, people can see what others are reading or thinking about.
Tagging may appear unorganized, but for the moment it's working. And as it gains more converts, it's helping people rethink what search means online. Green is Internet editor for BusinessWeek in New York