Totally inexperienced opinion here:<p>We&#x27;re in an advertising bubble.  Remember the ridiculousness surrounding the &quot;Yo&quot; app?  People running around in circles about how it can be a great way to increase brand awareness due to the simplicity of it all?  How it can connect with so many different apps?  Yeah ... it&#x27;s panned out <i>exactly</i> like its detractors predicted: sharp declines in downloads, hype is dead, and people have moved on to the next social app fad.<p>Another factor I&#x27;m noticing is international money.  Uber didn&#x27;t start approaching ridiculous valuation levels until Chinese investors started getting on the train.