Unfortunately, the reality is that children we often see selling things on a street corner are not even their own posessions.  I've been around the world and talked to many backpackers and we'ld always agree that these children were child labourers working for their parents.  The sad thing is, sometimes these children would be working all day and their parents don't even hold down a job.

Instead of children being children (and playing in the park), they are instead selling sea shells or bottled drinks to tourists, so the parents (especially father) can have beer money.  >:(

This is not all too uncommon a practice in N. America either, and is one of the many reasons why city councils don't tolerate children selling lemonade in parks and other venues.