I would be very excited to receive items from one of these robots. However, I don't know if I could bring myself to send anything of import. The risk of en route damage/theft seems really high. The trapping or taunting of them seems like a surefire activity for children. Their contribution to already congested pedestrian routes in urban areas seems like a perfect catalyst for sidewalk rage induced kicks. If they were to commonly transport high value goods, theft would be a huge issue. A few hours to build a serviceable faraday cage and you have a drop and lift job that nets significant gains. Not advocated theft, but it seems a rather obvious risk.

Also, dogs rejoice! You finally have a catchable, chewable mail courier.

Edit: There also seems to be some potential security risks here. Some cities may not be keen on unmanned, arbitrary payload carrying robots driving through throngs of pedestrians. They are going to have vet the store operators and detect if a recipient fills a unit with unexpected items. Maybe that is just paranoia.