<p><strong>One example where rich definitely do get richer <em>causally</em> (i.e. after controlling for quality), is questions, in particular newly posted questions.</strong></p>

<ol>
<li><p>The more upvotes a newly posted question gets, the more likely it is to be noticed by somebody scrolling down the front page, and hence to be opened, and hence to be upvoted.</p></li>
<li><p>If a newly posted question gets sufficient number of upvotes, it gets into the week/month hot questions list and is more likely to be noticed/opened/upvoted after it disappears from the front page.</p></li>
<li><p>If a newly posted question gets huge enough number of upvotes (and possibly a couple of answers too), it can get into the Hot Network Questions list which usually makes the number of views/upvotes <em>explode</em>.</p></li>
</ol>
