Venture capital companies Founders Fund and BlueRun Ventures joined forces to give Zivity the additional cash, which raises Zivity's total venture capital haul to $8 million.
Founders Fund was an early investor in social networking goliath Facebook.com. Both companies have invested in the photo-sharing network Slide.com.
Zivity.com uses social-networking tools to let models, adult and otherwise, share their images with a larger user base that votes on their attractiveness. Registered users must subscribe to the site to be able to vote, and about 40 percent of the sites revenue goes to the models.
The site is currently in private beta testing and can only be joined via invitation or application. The site is set to launch in 2009.