Ready to achieve serious scale, Pinterest has finally replaced its invite-only model with open registration. “One of the Internet's most popular social networks pushed its doors wide open today,” CNet notes. “This means users can sign up for an account without having to wait for an invite, the company said in a blog post.” Previously, potential pinners had to request an invite from Pinterest or be invited by a friend who already had a Pinterest account. Invites allowed the site to control the volume of new users so that its servers were not overwhelmed, according to Pinterest. “Now, the site can handle any new traffic that comes its way,” according to CNet.