SAN FRANCISCO — Mark Brooks wants the whole Web to know that he spent $41 on an iPad case at an Apple store, $24 eating at an Applebee’s, and $6,450 at a Florida plastic surgery clinic for nose work.
Too much information, you say? On the Internet, there seems to be no such thing. A wave of Web start-ups aims to help people indulge their urge to divulge — from sites like Blippy, which Mr. Brooks used to broadcast news of what he bought, to Foursquare, a mobile social network that allows people to announce their precise location to the world, to Skimble, an iPhone application that people use to reveal, say, how many push-ups they are doing and how long they spend in yoga class.
Not that long ago, many were leery of using their real names on the Web, let alone sharing potentially embarrassing personal details about their shopping and lifestyle habits. But these startups are exploiting a mood of online openness, despite possible hidden dangers.
“People are not necessarily thinking about how long this information will stick around, or how it could be used and exploited by marketers,” said Chris Conley, a technology and civil liberties fellow at the American Civil Liberties Union.
The spirit of sharing has already run into some roadblocks. Amazon.com was so wary of the security ramifications of Blippy’s idea of letting consumers post everything they bought that, for several months, it blocked the site from allowing people to publish their Amazon purchases.
In March, Blippy sidestepped Amazon by asking its customers for access to their Gmail accounts, and then took the purchase data from the receipts Amazon had e-mailed them. Blippy says thousands of its users have supplied the keys to their e-mail accounts.
There is no way to quantify the number of these start-ups, but they are the rage among venture capitalists. Although some doubt whether the sites will gain true mainstream popularity — and whether they will make any money — the entrepreneurs involved think they are on to something.
Blippy, which opened last fall, was the first to introduce the notion of publishing credit card and other purchases. Recently it attracted around 125,000 visitors and closed an investment round of $11 million from venture capitalists. It hopes to make money by, among other things, taking a commission when people are inspired to imitate their friends’ purchases posted on the site.
The people behind Swipely, a site soon to arrive and similar to Blippy, are also optimistic.
Swipely的性質類似Blippy，近期內就會正式運作。它的幕後推手同樣樂觀。
“We will help people discover a great restaurant or movie through their friends and make it easy to recommend their own purchases,” said Angus Davis, 32, a veteran of Netscape and Microsoft who is testing Swipely with a small group. “I really believe that the lens of your friends is fast becoming the most powerful way to discover things on the Internet.”
Mr. Brooks, a 38-year-old consultant for online dating Web sites, seems to be a perfect customer. He publishes his travel schedule on Dopplr. His DNA profile is available on 23andMe. And on Blippy, he makes public all he spends with his credit card, along with his spending at Netflix, iTunes and Amazon.com.
“It’s very important to me to push out my character and hopefully my good reputation as far as possible, and that means being open,” he said, dismissing any privacy concerns by adding, “I simply have nothing to hide.”
To Silicon Valley’s deep thinkers, this is all part of one big trend: People are becoming more relaxed about privacy, having come to recognize that publicizing little pieces of information about themselves can result in serendipitous conversations — and little jolts of ego gratification.
Still, only two years ago, Facebook members rebelled when the site introduced its notorious Beacon service, which published members’ online transactions back to the site — essentially the same concept as Blippy and Swipely. But there is the worry about identity theft.
“Ten years ago, people were afraid to buy stuff online. Now they’re sharing everything they buy,” said Barry Borsboom, a student at Leiden University in the Netherlands, who this year created an intentionally provocative site called Please Rob Me. The site collected and published Foursquare updates that indicated when people were out socializing — and therefore away from their homes.
荷蘭雷登大學學生波士鮑姆今年推出刻意具有挑釁意味的網站Please Rob Me（請搶劫我）。他說：「10年前，人們不敢上網購物。如今，他們已經樂於與別人分享網路購物經驗。」這個網站蒐集並公布Foursquare的更新資料，使網友得以掌握會員外出參加社交活動，因而不在家的時間。
“Times are changing, and most people might not know where the dangers lie,” Mr. Borsboom said.