Photo sharing social media site Pinterest has ended its invite-only registration process and is now available for anyone to sign on. The platform has been one of the fastest-growing social sites since its launch, becoming the third most popular behind Facebook and Twitter, according to an Experian study earlier this year.

While analytics wonks have been closely monitoring Pinterest’s growth curve, with some noting a recent slow-down, the site will likely spike in the near term now that the gates are open.

In hindsight, the company has been ramping up for the public opening by introducing new categories and broadening others. In July, Pinterest added to its category menu to include Quotes, Tattoos and Weddings. Other category names were expanded—Pets became Animals and Prints & Posters became Illustrations & Posters, for example.

And in May, Japanese ecommerce company Rakuten invested an Internet-bubble worthy $100 million in Pinterest, valuing the company at a reported $1.5 billion.