Having started in 2005 as  a sort-of platform for Arinana Hiffington's celebrity pals to write online (before the age of Instagram and Twitter), the Huffington Post is in post-Ariana phase now, who has left to work at another startup. 

The online news outfit somehow manages to churn out 1500 articles a day (yes), six times what the New York Times or Buzzfeed (started by ex Huff-post guy Jonah Peretti) publish each day. Another 'daily articles by numbers' champ is Henry Blodget's Business Insider. Copycats like Medium and Linkedin have also copied Huff Post's patented brand of 'celeberities' writing 'think pieces' on their 'platforms'.

What is the secret to Huff Post's productivity? 
John Oliver described it best: “Arianna Huffington’s blockquote junction and book excerpt clearinghouse.”