05/18/2012 10:43 am ET Updated May 18, 2012

Pinterest Joins The $1 Billion Club

Congratulations, Pinterest. Welcome to The $1 Billion Club.

After your $100 million round of financing closed Thursday, the total value of your shares soared to about $1.5 billion, vaulting you into an exclusive club of venture-backed companies that have reached or exceeded the $1 billion valuation mark. (I think this may entitle you to some sort of Billionaire Boys Club sweater vest or something.)

But don’t get too full of yourself.

Sure, Japanese e-commerce company Rakuten, the lead investor in your latest cash infusion, valued you at 1.5 times what Facebook paid for your cousin Instagram. But let’s be real here. These are heady times. The Club is losing its exclusivity. Membership has nearly doubled this past year.

At least 20 private firms now call themselves $1 Billion Club members, according to an analyst from the business and financial research firm PrivCo. It feels like they’re letting anyone in these days.

Don't get me wrong, Pinterest. You're definitely special. After all, you did recently cross 20 million users, up from 1 million in July 2011, with only about 35 employees. But to keep you grounded in these bubbly times, here are nine other tech startups that recently entered The $1 Billion Club.

All slideshow statistics brought to you by PrivCo.

12 Most Valuable Startups