I have never worked as a messenger (I never said I did), but my ex-husband did ... during the recession of the early 1990s. So the $$ value I mentioned could be a little low by today's standards, about 15 years later, but was just a number grabbed out of a hat anyway to make the point that couriers are paid per package delivered.

And what I do know for sure is that no couriers at that time were making a lot of money ... to me it probably seemed like he was making 0.30 a package. (Although I do know that one company he worked for, for a short period of time, was paying their employees about $300/month after all the deductions ... it was pathetic. The other companies he worked for were a bit better than that.) The only ones who were making what could be called "a living" were truck couriers because they could haul a lot and large heavy boxes were worth a lot more than an envelope. Nevertheless, my ex was busy all day ... and he knew the city very well.

Oh, and after taking off the amount for the radio rental, and uniform purchase, and buying stickers for your "vehicle", all the other little things the courier companies at the time required of their employees, the take-home pay could be about $12/day some days. But then, the early 1990s were tough years.

But that brings up something else ... to the OP ... if you decide you want to give it a go, before you sign up, check to see what the policies are on radio rentals, uniforms, etc. etc.