Pinterests recommender system algo (picture suggestions) is flawed/broken. It shows you always the same pictures, of the same k-mean group. And their nag scree

Pinterests recommender system algo (picture suggestions) is flawed/broken. It shows you always the same pictures, of the same k-mean group. And their nag screen to login/signup is as annoying as on Quora. Btw: Has Quora completed their pivot already, they joined YC like a year ago? http://venturebeat.com/2014/05/09/meet-the-oldest-y-combinator-startup-ever-quora/ http://venturebeat.com/2014/05/09/meet-the-oldest-y-combinat... Glad to see pg doesn't like the nag screen either: https://news.ycombinator.com/item?id=5217449 https://news.ycombinator.com/item?id=5217449 (full context: https://www.quora.com/Why-did-Quora-join-the-2014-Y-Combinator-batch https://www.quora.com/Why-did-Quora-join-the-2014-Y-Combinat... )