Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.
RevolverMaps is a collection of real-time visitor statistics widgets for website or blog. Interactive visitor mappings to a globe rendered by the Revolver Engine.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.