The origins of new internet fashions can usually be traced back to the technology elite of Silicon Valley or the digital media aficionados of New York â€“ not to women in the small towns of the American Midwest.
That makes the sudden rise of Pinterest, a website for collecting and sharing images, an intriguing anomaly. The popularity of the site, which first took off in Iowa â€“ a state better known for its corn than its computer code â€“ has grown rapidly in recent months among mainly female users.
They have taken to a highly visual design that lets them "pin" pictures found elsewhere online to thematic "boards" on their own pages. Arts and crafts, homes, food and fashion all feature highly on the list of pictures users copy from other websites. Many are then "repinned" by other users to their own boards, giving the images wider currency among a growing network of like-minded people.
"Cutting out pictures from magazines and putting them on your wall was something we all did as kids," says Julian Green, an internet entrepreneur who has experimented with similar ideas in fields such as travel and homes. "Pinterest has nailed the experience."
The site was rewarded with nearly 18m visitors in the US alone last month â€“ a jump of 50 per cent from the month before â€“ and is registering strong growth from a lower base in Europe, according to ComScore, a market research company.
It is too early to tell if this latest hot consumer internet company will be more than a passing fad. But it is becoming a standard-bearer for a class of internet site that is fast gaining a following among users, as well as the consumer product and entertainment companies that seek to follow them around the web.
Relying on what has become known as "social curation", such sites encourage users to exhibit the things that interest them â€“ often by selecting, saving and collating images, videos or articles from the wider web â€“ and then let others follow and copy them. Tastemakers are created almost overnight, their ideas passed around the world virally.
In fields such as fashion and travel, such sites have been springing up for some time. Polyvore, founded five years ago, was among the first of many rival sites to let users show off their fashion sense, while Houzz, set up in 2009, encourages its members to indulge their passion for architecture and decor.
"Social curation in 2012 has become quite the hot topic," says Chad Hurley, a co-founder of YouTube who is now trying his own hand at the idea. Along with long-time business partner Steve Chen, he recently bought and overhauled Delicious â€“ founded nearly a decade ago for users to store and share web links â€“ to reflect today's mix-and-match visual style.
The surfeit of information on the web has exhausted the scope of search engines, leaving users looking for ways to filter out what they really care about, says Mr Hurley: "Algorithms can only take you so far."
The immediate cause of this explosion of interest-specific online networks can be found in the rise of social networking, though its roots go back much further.
Early online destinations such as GeoCities, popular in the 1990s, grouped user-created websites into thematic areas and gave users a way to find and spread information among themselves, says David Karp, a New York-based internet entrepreneur. Tumblr, the microblogging site he founded and heads, seeks to emulate that by letting people create streams of short multimedia posts that others can follow and copy.
Google's search algorithm introduced a fresh way of filtering online information. By making it possible to find answers to questions quickly, it cut through the need to join networks to dig up relevant material.
But with the rise of Facebook and Twitter, things are turning full circle. Networks of friends and contacts are becoming a powerful reference source, particularly for topics that are too subjective or personal to be caught in Google's mechanistic analysis of the web. It is in this new world that Pinterest has taken off. "It's capturing a behaviour we think is really powerful: people discovering real-world things, with a social overlay," says Jeff Jordan, a venture capitalist and former head of online payment company PayPal who now sits on Pinterest's board. It has become a site for showing the world "things you want to buy, places you want to go", he says.
While Pinterest says it has put off thoughts of making money till another day, the commercial possibilities raised by this aspirational behaviour have already excited a band of online copycats. Getting users to congregate around specific interests, proponents argue, will draw more targeted (and valuable) forms of advertising. Product recommendations could also boost online sales.
So goes the theory. Most advertisers have yet to decide whether these user-curated sites are a good place to do business. "None of us has really proven it," says Mr Karp. "We're not paying all the bills yet."
The entrepreneurs and venture capitalists crowding into this area all share a simple belief: if users come, the money will eventually follow. "People want much more curated experiences, where they feel they can drive more of what it is they consume," says Roelof Botha, a partner at venture capital firm Sequoia Capital who has invested in companies such as Tumblr and Houzz.
According to their backers, these interest-based networks will eventually supplant not only the first generation of internet portals, such as Yahoo, but also the centralised networks of the old media world. "It's not about Fox or CNN any more â€“ it's not the big networks," says Mr Karp of Tumblr. "It's these communities of like-minded people."
Yet while these sites claim to have grabbed a sizeable slice of their audience's attention â€“ for instance, users clock up six times as many minutes on Tumblr as on Twitter, for instance, according to ComScore "they still face many questions. Among the biggest is whether they can survive in a crowded world with almost no barriers to entry and whether they can rise above what has become the curse of the online network world: a rapid fading of interest as users turn to newer generations of fashionable sites.
The new band of social curation sites tends to follow a common model. Users create accounts, often signing in using their Facebook credentials, and start to post on their pages. Others then "follow" those they find most interesting. Content that is reposted by followers generates much of the action: 80 per cent of the images on Pinterest are "repinned", for instance. It may feel lazy â€“ or even like plagiarism â€“ but this restless filtering and refiltering of the web has become a way to uncover and pass on things that might otherwise have lain buried.
Twitter, with its follow button and "re-tweets", has long relied on such features. But a strong visual style, along with the ability to post a wider range of material â€“ including videos and larger bodies of text â€“ directly into online "feeds" or on static boards sets the newer social curation sites apart. Many also limit themselves to a narrow range of subjects, seeking to tap into big online markets such as travel and property.
Social curation sites diverge from social networks in important ways. They rely in part on symbiosis â€“ by letting people sign in with their Facebook account, for instance, many make it easy to invite friends to join or to gain attention for themselves by posting information about a user's activities back on their Facebook page.
But they also seek to reach far beyond the "social graph", or network of connections, that lies at the heart of Facebook. "We're not focused on relationships â€“ it's more about interests," says Mr Hurley. "Hopefully like-minded people can meet each other. It's not just about what your friends are doing."
By presenting more visual user interfaces and making it easier to identify and follow people with similar interests, they also hope to cut through the tides of information that can make the more established networks hard to navigate.
"Facebook and Twitter have a ton of information they're trying to make sense of," says Mr Hurley. "There's enough to go around for everyone."
Whether many can survive in a world where there is ever increasing competition for shortening attention spans, however, is a different matter. In particular, Facebook's expansive reach and high levels of "engagement" â€“ its users spend six to seven hours a month on the site, according to ComScore â€“ has threatened to suck much of the focus away from others seeking to grow in its shadow.
But, while Facebook's social graph is a powerful inducement to get people to return constantly to stay in touch with friends and family, the "interest graphs" of sites such as Pinterest â€“ linking like-minded people â€“ are also proving a compelling lure.
This gives the lie to the once widely held view that all social behaviour online would eventually be drawn into a small number of networks led by Facebook, says Mr Botha of Sequoia. "It's the emergence of multiple graphs: there isn't just one graph," he says.
How many of them will be around for the long term is another matter. Fashionable online networks "the likes of MySpace and Bebo â€“ often fade and die as newer forms of online interaction become popular. Historically, the "half-life of online networks" has proved to be extremely short, says Mr Karp of Tumblr. "We've never seen one of these networks on the web last more than 10 years."
Facebook hopes to buck that trend by setting itself up as a utility that other sites can plug into, drawing on its big user base and social connections. Like favourite restaurants that become local institutions and last generations, there is a place for such destinations on the web, says Mr Botha. But most of the sites where users come to network will be more like nightclubs, he adds, coming and going as fashions shift.
It is still too early to tell whether Pinterest, the latest hot new club on the block, will follow this pattern. For now, the network effects are clearly working in its favour as users flock to the site. "It becomes self-sustaining," claims Mr Jordan, who says Pinterest has moved quickly beyond its original audience of Midwesterners. The more users connect to each other and share pictures, the more the behaviour feeds on itself.
How long the party will last, though, is anyone's guess.
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