Under the terms of the agreement, Hearst will get several sites that fall under the eCrush umbrella. These include the original eCrush site, eSpin - a profile-based flirting site - and the HighSchoolStyleBoard photo-rating site.
The company is keen to get its hands on eCrush's one million monthly unique visitors - nine out of ten of who are 13-19 years old - as part of its push into the US teen market.
To help this push later in the month it will launch MyPromShopper.com, a prom-planning destination, and in February it will unveil revamped sites for its three teen magazines CosmoGIRL.com, Seventeen.com, and Teenmag.com - all heavily incorporating Web 2.0 features.
Chuck Cordray, vice president and general manager of Hearst Digital, said: "As social networking and interactivity online become an integral part of teenagers' lives, we want to be everywhere they turn.
"The addition of the eCrush Network enables Hearst to broaden our presence in the online arena for teens and become a true destination for everything from fashion and beauty to advice and community."
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