If companies need advertisements to inform potential customers, let them do that in an appropriate place. For instance, an adds booklet.
Allowing companies to use the public space to advertise is not in the interest of the populace: it stimulates overconsumption and it creates distracting stimuli in an environment that is already very busy. It also facilitates unfair competition when advertising space is sold to the highest bidder, since company wealth supersedes product quality or utility.