Buzzfeed

 Buzzfeed  is a meme, news, and entertainment site.

Reactions
Buzzfeed has a system for quickly posting a a "Reaction" by clicking one of several predefined buttons. A user can assign up to three reactions to each post. Reactions inform buzzfeed's recommendation algorithm.

These buttons are shown on memes and listicles, but do not appear to be present on more serious Buzzfeed News articles.