[ddlatham]

One significant difference between this new point-of-sale prompt for a tip, compared to previous customs is that this is now asking for the tip before you receive the product or service on offer. This means that you do not yet know how your service will be, but you are being asked to tip. Also, you now worry that if you do not tip, you risk a negative response - like slower service, or worse.

When we tipped for table service at a restaurant, or a haircut, cab ride, etc, we already had received the service and could tip based on our level of appreciation, without fear of retaliation.