Amar Nath Barman was the guy who puts the shopping catalogue in your mailbox. Like thousands of others, he walked kilometre after kilometre stuffing the advertising pamphlets he had folded the night before into letterboxes.

In return, these walkers typically get paid a rate per 1000 households, with one industry insider saying it would take about five hours to complete the round. For that, a walker could get a total payment of as little as $20 on a weekday and $12 on a weekend, when the volume of pamphlets is smaller.

This rate, which is well below the minimum wage, is defended by the companies involved, which argue that the walkers are independent contractors. But the reality for the people walking the street is that they may have limited employment options and often end up fighting just to get the pay they are owed.

“I have tried three different companies - all did the same thing. They pay me for the first day or two and then stop, even after many days of work for them,” said Mr Barman, an international student from Bangladesh.