That is the stupidest fucking idea I have ever heard...
...even more-so since regular shipping can be virtually anonymous, and more secure and less suspicious...
I agree, passing on a parcel would be slow, bureaucratic and victim to high levels of theft, why bother passing on a parcel for change if you can claim to have passed it on and just steal it then sell it on ebay or the like?
You don't get paid until you scan the code of the next person in the chain. If you just take the package, all you get is a package and ruined reputation, since the system will know who was the last person to take it.