&gt; Right now, a reply to Justin Bieber by a 16-year-old fangirl goes into the ether, never to be seen again. There is zero incentive in the product to interact with celebrities on Twitter, because no one will see the responses.<p>This seems like speculation. Empirically, do a search for &quot;@justinbieber&quot; (click on &quot;live&quot;) or look at any of his tweets, and you&#x27;ll see innumerable 16-year-old fangirls who have found some incentive to tweet at him. There&#x27;s also the subphenomenon of these 16-year-old fangirls getting incredibly excited when those tweets <i>do</i> get seen and interacted with, which indicates, one, that they don&#x27;t go into the ether, and two, people have a genuine hope of interaction.<p>I&#x27;ve seen this in practice, because I do actually follow certain parts of popular culture and music and trashy television (not Bieber, as it happens, but enough others) and occasionally look at what they&#x27;re up to on Twitter. It happens without fail for <i>every</i> celebrity.<p>So I wonder if the author is actually reporting on how actual people actually use Twitter, or extrapolating from the eyes of a non-16-year-old non-fangirl who cares about things like reply threading.