Weird that they use this as Quora's 'onboarding'. I bet they get most of their signups/onboarding from the annoying SEO spam they have with the "signup to see more than the first answer (or close this annoying popup box to see that magical first answer)" popup.
Google needs to give the entire Quora site a large negative ranking Rapgenius-style.
For those that haven't seen it: http://i.imgur.com/vbLTXYz.png