We fear missing out. We crave suspense. For a Millennial generation that is highly skeptical of institutions, live content is a breath of fresh air, serving up unfiltered content that is stripped of any manipulation or deception. What is seen is what is true. Unscripted.
If you're not currently an undergraduate it's possible that you've never heard of Yik Yak. But if you're a current undergrad, it's pretty much impossible that you haven't heard about Yik Yak.