&gt;how do you set a tip for a service not yet performed?<p>As if tipping had logical regularity to begin with? You&#x27;re expected to tip at coffee shops long before receiving the service, and for takeout orders, where there is no service. (At least, they try to dupe you into thinking it&#x27;s expected.)<p>&quot;Add a tip to this order when placing it&quot; sounds stupid, but it&#x27;s only <i>revealing</i> the pre-existing stupidity of the convention it&#x27;s trying to parallel.<p>If they go the other route like Uber and say &quot;tip&#x27;s included&quot;, then they trigger an angels-on-a-pin lawsuit about &quot;well which part was the tip because you can&#x27;t take a cut of that&quot;.