One of the first things I learned when I was a young busker, was that there exists something like a busker mob. I was busking at the exit of a supermarket, earning a conspiciously large amount of money. Then I noticed that everyone leaving the supermarket had change in their hands, because you have to put a coin in the shopping cart to unlock it, which you get back when you stall the cart again. When people already have a coin in their hands when passing a busker, they are more likely to throw it in your guitar case, than bothering to dig up their purse to put it away. Now, I wasn’t the only busker that discovered this lucrative busking spot and after a few minutes another busker arrived and told me that this was HIS turf and that I had to pay him if I wanted to keep playing there. If I didn’t, he told me in vague terms that something unpleasant might happen to me. He actually tried to let me pay some kind of protection money. Of course, I quickly left like the cowardly youngster I was back then. I feared someone named Fat Mickey or Louie the Knife would come and break my fingers.
So… let this be a warning to you all: when you find a spot where you collect more money than avarage, you’re probably not the first one, nor the only one to discover this. Chances are this specific spot is controlled by the Busker Mob, so either join the gang or find somewhere else to play.