[treyp]

yes, but obviously that's not the comparison. shipping services have much longer distances to travel, they have the overhead of the entire system (trucks or planes for the long haul, trucks driving to your delivery address and from the pickup address, the associated costs of all the time spent by all the people involved) to overcome. i'm not sure who exactly wins in the end without real numbers.

and again, packaging should not be underestimated either.

[InclinedPlane]

Your goods come from somewhere regardless, and whether they are delivered to a store or to your home they have to travel that distance just the same. But with delivery trucks the miles driven by the trucks are amortized over all of the deliveries made.