&gt;<i>The difference is uncertainty. With pizza, you know pretty well what you are going to get.</i><p>Two counter-arguments:<p>People buy enticing stuff off of supermarket shelves all the time though -- things that they are not certain if they&#x27;ll like them.<p>Lots of people who have bought and generally like an app (or so they say), still complain for its price on boards, even if it&#x27;s comparable to a beer. E.g. they ask why a $2.99 app isn&#x27;t $0.99 etc.<p>So it&#x27;s not just &quot;uncertainty&quot;.