Delivering to a bunch of vehicles on one street or hitting a bunch of vehicles in one lot/garage is better than one fill per location.

It seems like they shouldn't be targeting consumers except as a means to target small businesses and municipal fleets.

Modern fuel pumps are slow compared to the old ones. (Seriously, if you stop at a gas station with the old style pumps it'll blow your mind how fast they are.) Sending someone to put 20gal in a van takes at least 20min assuming a few minutes driving. @ $9/hr that's the same labor cost as a $3 fee. Paying these people to come to you and fill your fleet of vans costs the same but is more convenient and ensures you get the lowest local price.