At a restaurant, people expect you to leave a 15 percent tip, or even 20, if the service is stellar. But these days, some servers are insulted if you leave less than 25 percent! And restaurants that estimate the gratuity for you often include an option for 30 percent. 

That may seem surprising, but a study by Cornell University found that more than one-third of customers already leave more than 20 percent - and only leave 15 when the service is truly dreadful.

The gradual increase even has a name: “Tip creep,” and it’s been going on since the turn of the last century. When tips first popped up in the late 1890s, they were considered “organized blackmail.” And if you didn’t tip, heaven only knows what would happen to your food the next time. But by 1918, it was standard to leave 10 percent. By the ‘60s, the average tip was 15 percent, and it’s been creeping higher ever since.

How come? 

For one thing, restaurant servers are often paid less than minimum wage, way less. So, they literally need the tips to make ends meet. So, restaurants have been encouraging gradually, bigger tips.

Also: Customers tend tip more at local places they visit often, as well as restaurants with cheap eats, because they know that the lower the prices, the lower the tip. And a lot of people tip generously because they’ve waited tables themselves, and know what a hard job it is.  

So, what do you usually tip? Would you go as high as 30 percent for great service? Weigh in at Facebook.com/JohnTesh.