Businesses who use iPhones/iPads and the Square app can add in pre-determined tip percentage amounts that you can tap to add to your total when you're cashing out, after your card is swiped. Usually, I see the suggestions of 15%, 18%, and 20% plus each respective dollar amount. But lately, I have noticed more and more businesses making the suggested percentages 22%, 25%, 28% (for example). If someone wants to tip the standard 18-20%, you have to tap "Other" and then either enter your own percentage or dollar amount. And often, the merchant is standing right there watching and waiting for you. It makes it awkward and its a little nefarious to make the set percentages this. I bet it forces some people into just selecting 22% because they don't want to hassle with changing it.
Also, I just purchased tickets to a brunch in Vegas on Sunday to watch football. The tickets were $75 each which is a $75 food and beverage credit. They added 18% when I bought the tickets, and another 35% for "service" the day of. That was a tough one to swallow!