I feel like I should save all of the Fifty Shades of Grey posts until the section on kinks and paraphilias, but there are too many hilarious spin-offs to wait. I mentioned Fifty Shades of Grey in class a couple of weeks ago. It started as Twighlight BDSM fan fiction, and became a viral phenomenon. It was eventually picked up by Random House and has sold almost 50 million copies worldwide. This is despite the horrifically bad writing and completely inaccurate depiction of BDSM. The novel has been credited with rekindling the sex drives of many, many middle-aged women (these anecdotes come from sex and relationship therapists).
This clip was passed along by Conrado (thanks!). It's full of NSFW language and is loud!