I did it for 1 summer in 1977 in LA at the Redondo Beach pier. Purely for survival. I was living in a Toyota Corolla that I kept parked in the pier parking lot. I was 17 and had just graduated high school. It was a great experience. Times were different then. Several times per week someone would come by with a guitar or harmonica and just start jamming with me or singing harmony for an hour or so. Not a single one of them would accept any of the donations we got.
Those days left me with a great appreciation for those who do it. Every summer I make at least one trip to NYC and I always carve out a Saturday afternoon to roam around Central Park to check out the buskers. If you haven't done it, I highly recommend it. There are folks out there as good as anything you'll hear on the radio.