Comedy Central's Stephen Colbert, poking fun at people who bare minute details of their lives online, rattled off some of the more "riveting" updates on Blippy.com, a new social networking site that lets people share their spending habits with friends.
"$10.94 at Wendy's."
"$7.68 at Panda Express."
"Wow, this is more exciting than going through old receipts," Colbert cracked during his late-night show last month. "It's going through new receipts."
Even in this exhibitionist age, Blippy is stretching social norms by asking people to disclose information that used to be off limits: personal finances.
The site's converts say they discover new products and good deals while connecting with their friends. Los Angeles-based Web celeb and self-described iPhone applications addict Justine Ezarik, 25, said she got hooked on Sleep Cycle, a popular Swedish-designed app that tracks her sleep patterns, after she saw a friend buy it on Blippy.
"A lot of people are skeptical. They feel like they are sharing so much online already," Ezarik said. "I just feel like this is the next thing to do."
Privacy watchdogs warn that social networking sites such as Blippy give online voyeurs and data miners an intimate window into people's every move, putting them at risk for identity theft or intrusive marketing.
"A wise consumer should treat what they buy and spend as a private transaction," said Jeffrey Chester, executive director of the Center for Digital Democracy.
Blippy says it knows its success depends on keeping consumers' information safe and has taken significant steps to protect sensitive data. It declined to be more specific, citing competitive reasons.
Blippy's founders are wagering they can shift consumer attitudes. After all, the rise of online social networking has quickly and profoundly transformed how people communicate.
Every step of the way, critics have sounded the alarm that social networking sites are peeling away the last shreds of online privacy.
Yet, the popularity of sites such as Facebook and Twitter is exploding. These sites connect people in every corner of the global Internet and encourage them to open up in ways that just a few years ago would have been unthinkable.
As a result, more people are blasting increasingly personal information -- their thoughts, plans, whereabouts, photos -- onto the Web.
"People are sharing more and more on the Internet because they are getting so much benefit from it," said Philip Kaplan, one of Blippy's three co-founders.
It has become practically antisocial not to share. And part of what people share is what they buy, he said.
Facebook caused an uproar when it tried to capitalize on friends' business referrals in 2008 with Beacon, an online tool that tracked the purchases and activities of its users on dozens of websites without their consent.
Unlike Beacon when it launched, Blippy offers its users granular control: You only share what you want to share. You register a credit card or accounts at such sites as Apple's iTunes store or Netflix.com to begin streaming transactions in a Twitter-like feed. You can opt to share those transactions with the public or just with your friends or hide individual purchases. You can also pause your Blippy stream.
Some purchases are humdrum: gas or groceries. Others are more conversation-starting, like Kaplan shelling out 99 cents for the iPhone game Doodle Jump, $163 for a Wi-Fi enabled scale on Amazon.com or $70.06 for a sexy gift for his wife at a little store called Does Your Mother Know in San Francisco's Castro district.
One group of users held an impromptu contest to see who could find the cheapest item online. They ultimately pounced on a 5-cent HDMI cable on Amazon.com (plus $2.95 in shipping costs).
"From the user perspective, it's just a stream of cool stuff that your friends are buying," Kaplan said. "From the business perspective, it's the ultimate word-of-mouth marketing: I buy something and tell all my friends about it."
Users are now streaming more than $1 million a week in purchases, Kaplan said. They sometimes discover just how revealing those purchases can be.
Joe Greenstein, the 32-year-old co-founder and chief executive of Flixster.com and a Blippy advisor, didn't need to change his relationship status on Facebook in December when he broke up with his girlfriend. His friends found out he was single when he downloaded the iPhone application for JDate, an online Jewish dating service.
Blippy launched to the public in January with a small number of users -- 2,500 -- and big-name backers. The Palo Alto company has raised about $1.7 million from venture capital firms Sequoia Capital and Charles River Ventures and angel investors Twitter co-founder Evan Williams and Mahalo.com founder Jason Calacanis.