"Popular culture studies is the academic discipline studying popular culture [a.k.a. pop culture] from a critical theory perspective. It is generally considered as a combination of communication studies and cultural studies. ... Conceptual barriers between so-called high and low culture have broken down, accompanying an explosion in scholarly interest in popular culture, which encompasses such diverse media as comic books, television, and the Internet."
Know Your Meme - general,non-academic history of viral images and videos
If you are having trouble finding good quality sources on a specific trend, web site, or video game, research its history. Although it may seem as if they pop out of nowhere, all ideas have a past. Find its roots. Put it into context.
Research the creators or developers - what other content have they made? Is it in the same genre?
For disruptive ideas, research the industry it is transforming.
Has someone borrowed a concept or process from another industry or culture? Look into its original context.