Buy and sell enough goods on eBay and you'll accumulate a score based on feedback left by other users. Visit another site, however, and you must rebuild your reputation from scratch.
A Boston-based startup is trying to change that with a reputation system that travels with you, whether you're seeking roommates at a classifieds site like Craigslist or love at a dating site.
"We believe reputation is something that needs to be horizontal," said Shawn Broderick, chief executive of TrustPlus Inc. "If I'm a good buyer on eBay, that should be reflected when I'm on Craigslist."
People who've had dealings with you can rate you using your e-mail address, eBay Inc. username, telephone number or another identifier.
For example, someone who bought a couch from you on eBay can leave feedback using your eBay ID. Someone else who received computer repair services from you through Craigslist can rate you based on the e-mail address you used.
The company also is partnering with smaller classifieds, commerce and other sites to incorporate reputation data they already have on you. (It doesn't have deals, yet, with larger sites like eBay).
Meanwhile, users of the online hangout Facebook can pull up your combined reputation score by using the e-mail address, which is the Facebook login. So can an eBay user who knows your eBay username.
The service is free, though the company is looking to provide premium services for Web sites and sellers, including the ability to process credit cards.
TrustPlus will give users some privacy controls. They can choose to keep some of their identities in silos — for instance, if they don't want to mix their dealings on Facebook and eBay.
However, people can choose to rate anyone, and there's no guarantee that person will know they must visit the TrustPlus site to turn on those privacy controls.
"I won't claim we have everything sorted out, because we don't," Broderick said. "We're learning as we go."