Referer spam has been around since at least 2002 when Wired wrote "When the spam hits the blogs" and even interviewed little ol' me about it. The nuisance was taking off then, and as many blogs had automatically updating link lists on their blogs these might have been the ultimate target. Because honestly now, one person checking their logs on occasion does not a great target make. Similar tactics are used to do trackback spam, which then allows the spammed link to appear in the targeted blog.
Back in 2002, this is what Pollak said:

Remember this? Cuckoo for Instagram likes? Then download firegram, right now at Techcrunch? That was the rolling start of a good idea™ designed to solve one wee problem Instagram had. As people maxed out their hashtags, searching "sunset" brought you thousands of sunsets but also junk that had no sun at all in the image, making searching tags ever more useless. Why are people tagging so much? To get likes. And on night it dawned on iAdam that if he made an app that people could only choose one tag for the photo, but then blast it, making the image end up in the top 150 in searches for that tag.. attention-seekers will get their fame and people looking for sunsets will get that. Awesome!

Thank you @VFXrex for your astute image observation earlier on twitter..

In case you're scratching your head about those green twitter and facebook avatars popping up, allow me to illuminate.

Visual analytic tool allows companies to track what parts of sales videos are viewed most often.

Laguna Niguel—Simian, the global leader in creative workflow and media management solutions has developed a new tool that helps creative companies accurately pinpoint which parts of their sales presentations are garnering the most attention.