This as been happening in France also. We were also never giving tips before because there is a minimum wage but now, almost every bar & restaurant do it.

I wonder if it is not some form of US cultural influence. We see people tipping in series, films and such and start to do it to.

The credit card machines are probably set up to prompt the waiter for a tip. This is a common feature on POS systems, regardless of whether its sold in USA or Turkey.

Naturally all the machines support it, but it's up to the owner of the business whether to enable that feature or not.

Many don't even bother to turn the feature off ..

It is I almost always tip in cash, a lot of restaurants do sketchy stuff with tips given via card payments - I suspect Finland and the Nordics might be better though.

It's another case of importing American things you see on the TV every day.

Same is happening with Halloween now.