I worked at Fenway Park as a vendor for 8 years - 1969-1976.
I received one tip for the entire time, one.
A guy gave me a dollar. He must have been a Rockefeller, maybe he was drunk.
The pay was all commission - 10%.
If you were selling ice cream in April you might run up and down stairs for 3-4 hours and make $3.00 for the game.
If you were selling beer in August you might make $20 or $25 for 3 or 4 hours.
I think these vendors make very good money in tips now. Times change.