> Sure, but you can't force by law those decrepit buildings along the Minhocao to repaint.

Hum... Technically you can. The fight would really not be worth it, but the city can pass a law that fines eye-sores.

Anyway, you seem to want something aligned with my first comment up there of conditioning ads on a well maintained structures. That would very likely work too.

About advertisement, it is one of those industries that look like if they reduced by orders of magnitude the value they provide would increase. If that's the case, the right thing to do is to allow it, but tax it heavily (so all of those proposals are quite good). But "looks like" is a bad basis for actual policy, real data would be much better.