AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Amazon Advertising (formerly AMS or Amazon Marketing Services) is a service that works in a similar way to pay-per-click ads on Google.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
Spotify Widgets provide an embeddable view of a track, artist, album, user, playlist, podcast or episode for use within your web project.