Wishing for ultra-fast delivery with no tipping is NOT the same as wishing for tipping to go away altogether. Tipping is helpful when there is likely to be a h

Wishing for ultra-fast delivery with no tipping is NOT the same as wishing for tipping to go away altogether. Tipping is helpful when there is likely to be a high variation in customer service. In a small-item delivery scenario the customer-vendor interaction is 0-15 seconds. How much tipping variation do you expect there to be?