User: What are the advantages and disadvantages of allowing people to perform delivery tasks by walking instead of requiring the use of a bike or car? When do you think it is more pragmatic for deliveries to be fulfilled by walking versus biking or driving?
Assistant: There are both advantages and disadvantages to allowing delivery tasks to be completed by walking instead of biking or driving. The following is a list of advantages and disadvantages:

Advantages:
- Additional supply of individuals capable of performing deliveries (i.e., people without a bike or car)
- Potential for shorter delivery times in densely populated metropolitan areas
- Positive impact on the environment and sustainability
- Stronger contribution margins for shorter deliveries

Disadvantages:
- Weather can heavily impact if items are delivered or not as well as the quality of items when delivered (e.g., wet paper towels)
- Limitations on the number and weight of items being delivered
- Less deliveries can be performed together (i.e., batching of deliveries)
- Distance items can be delivered is substantially shorter

Overall, permitting deliveries to be fulfilled by walking likely provides incremental benefits in certain situations, especially in densely populated urban centers. However, it is not feasible to deliver items by walking in suburban or rural areas given the distance that needs to be covered to successfully deliver items.