It's a logistic mishap: when passersby stop to purchase an orange-juice, they aren't eager to share their data with the street-seller. In my country, it could be even dangerous. On the other hand, people who purchase food and drinks in the street are in hurry, so not eager to stop for more time above the purchasing. Worse in the case of people who put a penny into the street-musician's hat. They put the coin and go. They won't stop to wait for the musician to finish the show to share their data for the billing. And in the case of third and fourth-aged, no patience and no such a habit. This pitiful government is pushing the smallest entrepreneurs to informality again, despite claiming the compulsory billing will improve the formal jobs (it could if only would start a change on the kind of billing, requiring, for ex., only the nationality of the customer as years ago the Municipality billing did and exempting the street-artist to bill). Thank you for your support, dear friend♥️