If I am at a store I frequent that has a loyalty program, I don't mind giving them my phone number. Then they say, "Mike?" I say yes, and I'm on my way. If I am not in a store I frequent, I say, "No thank you". they usually say OK and move on. If they get pushy, I ask for a manager. I have never had them call for a manager; they continue checking me out.
WHEN I AM NOT GOING THROUGH A SELF CHECKOUT, THAT IS.
The other thing that really pisses me off is when I stand in line to buy, for example, coffee, and the kid behind the counter spins the screen around to face me asking how much of a tip I want to leave. Sometimes "No Tip" is an option, and sometimes I have to select "custom amount" and then add zero. With one exception, I refuse to give a tip for counter service. There is a soft serve ice cream place very near me called Pineapple Dream. I go there frequently. The kids that work there are always SO friendly and truly happy that you came in, I always put something in the tip jar. I have met the owner, and he told me that he interviews and selects his employees carefully and that he pays them enough that they are happy to be working there. I walk out of there with a smile on my face every time.