Children sometimes need pocket money for their needs. The problem is that they don't know how to earn them.
At first, they can work at shops as loader if he's strong enough. Secondly, he can work as promoter but it needs more time than previous variant and depends on luck and other people attention. Also they can work as thralls (подобие швейцара) for people who needs help with some things. At last, they can work as couriers at many places where their help is really good because of employers needs and requirements.