https://www.cnbc.com/2019/03/22/pinterests-ipo-filing-shows-dependence-on-google-and-facebook.html

Pinterest on Friday released its IPO prospectus, and the document shows just how much leverage Facebook and Google hold over internet companies.

Like many websites and apps, Pinterest allows users to sign into its service using their Facebook and Google credentials. The company relies on traffic from Google's search engine and logins from Facebook, which has over 2.3 billion global monthly active users.