I’m not sure how that is more of a problem than what Uber faces for the moment: imagine a bike messenger (heavily branded as it seems they are going to be) facing a parcel that isn’t ridiculously large, but still not ideal to carry in a messenger bag — smaller than a carry-on luggage. Shouldn’t he be able to say: “Look, I can strap that and risk crashing your box, or for $3 more I can ask this Uber driver who’s idle right now to do the delivery for you. He’ll be here in three minutes.”