This master thesis provides an in-depth analysis of the fanfiction phenomenon in re-lation to both the Internet and fan communities while touching upon the connection between novels and fanfiction, and how they shape each other. The first section of the thesis de-scribes what fanfiction is and the main criteria for something to be considered fanfiction. It delves into the historical development of fanfiction, tracing its roots and discussing the role of the Internet in its popularization, while also taking a look at common fan practices that surround it. Furthermore, it examines the way knowledge and tropes are communally shared in the context of fanfiction, how alternative universes are constructed, and the core differ-ences between the terms canon and fanon. In addition, the first section of the thesis also touches upon the topic of female sexuality and how young women express themselves through fanfiction. The second section of the thesis takes a more critical approach towards fanfiction, bringing to light the problems of intellectual property and the capitalist context in which fanfiction is produced. Moreover, this section places fanfiction into a cultural con-text of today, connecting it with the romance novels of the past. Furthermore, it examines the implication of commodification in fan communities through the lens of Fifty Shades of Grey, the book that started its life as Twilight fanfiction and then became a global phenome-non. In addition to that, using the concept of BookTok as a source, this section also takes a look at how the publishers and authors are starting to market their original novels in the same way fanfiction authors describe their fanfiction, The thesis concludes on a note that fanfiction is conceptually moving more and more towards the form of proper novels while novels are taking sharp turns towards presenting themselves in a similar way as fanfiction does.