Fab.com has doubled its membership to 3 million consumers since January and will generate $100 million in revenue this year, says Jason Goldberg, founder of the members-only flash-sale operator.

He says Fab.com, which launched in 2011 and sells home décor and other designer products, sold an average of 154 products per hour during its first nine months of operation.

Goldberg says member referrals are leading to membership growth for Fab.com. Members can earn credits on the site for referring friends; members earn two months of free shipping if they refer 50 consumers. Fab.com credits 50% of its sign-ups to social media referrals. Fab.com has a Facebook presence and also runs a feature on its site that enables shoppers to view, share and comment on what others are buying.

That kind of social reach recently drew the attention of Universal Music Group. The record label worked out a deal with the e-retailer to sell pop star Madonna’s new album for $7.99, 47% off the suggested retail price. Consumers could download the album or have the physical disc shipped free. The sale began March 26 and ran for six days. A Fab.com spokesman says the site’s traffic at least doubled during the sale period. “Madonna’s team recognized Fab’s meteoric growth, singular focus on design and use of social to build buzz around products and membership,” he says. “It’s why they turned to us as opposed to other sites for this.”

Fab.com was featured in Internet Retailer’s Hot 100 magazine issue, which highlights the most innovative online retailers of 2011.

Scott Ballantyne, Fab.com’s chief marketing officer, will speak at the Internet Retailer Conference & Exhibition this June in Chicago in a session entitled “Going social from Day One: How a start-up online retailer gained 2 million members through social marketing.