SlideShare is a web-based slide hosting service that allows users to upload PowerPoint, PDF, Keynote and OpenDocument presentations privately or publicly. Uploaded slide decks can be viewed on the site, mobile devices, or embedded on other websites. SlideShare sees high traffic with nearly 60 million unique visitors per month and over 16 million registered users. It also sees heavy daily use of uploaded videos and user engagement features like comments and subscriptions. SlideShare competes with services like Scribd, Issuu and Docstoc and is used by organizations such as The White House, NASA, and various businesses.