I think this also illustrates a huge issue with venture capital; it can be incredibly reactive, with funding reflecting short-term trends rather than long-term value.
Everything appears obvious in hindsight, but I wonder how Yik Yak could be valued at even close to $400 million. I can't imagine the intrinsic value being that high. What's the path to monetization? A solid userbase? Anybody I know that used it, used it for maybe a week…