He could be flirting or he could just find you interesting. When I was a barista I would chat up and give free food to customers I liked the personality of. I had a light crush on one customer but I treated them the same as my other favorite customers. When I got real nervous/blushy was when one of my favorites started flirting with me each time they came in, then I felt embarrassed/awkward around them. I still wanted to give them that "you're one of my favorites" treatment but it comes off as flirting back.

I really doubt it's a scheme to get more tips. I get the feeling by expressing that you seem older they were hoping you were closer to their age/in the age range to go out with. Some people have naturally flirty personalities so I could be wrong and it could just be that he finds you interesting as a person