&gt; Why? Do you often tip other random working-class people when it&#x27;s not expected, like cashiers in grocery stores?<p>Generally you tip when someone provides you with a service, and especially when they&#x27;ve gone above and beyond the base &quot;experience&quot;.<p>A cashier isn&#x27;t really providing a service... they&#x27;re collecting money for the store.<p>Baggers, however, provide a service, especially if they walk the bags to your car. Servers in restaurants provide a service, as they are in charge of your dining experience. Handymen that fix things in your house provide a service, etc.<p>In theory, you tip because you got an excellent experience. The chance of a good tip is, in theory, what motivates service providers to go above and beyond the bare minimum. If it&#x27;s a repeated service (like you dine at your favorite restaurant often), and the service provider knows you tip well for good experiences, it provides a good incentive to keep providing excellent experiences.