&gt; <i>Ads are much less an intrinsic cultural phenomenon than you think. We think they matter to culture simply because they exist, but their absence has no important effect on it.</i><p>The thing is, though, every culture, every city, is different, and <i>you just don&#x27;t know</i> what the effect will be until you&#x27;ve done it.  Maybe Tokyo and other Asian cities would turn out to be the same as São Paulo, but ... maybe they wouldn&#x27;t.<p>Because of this, and because it would be a <i>major</i> change, it&#x27;s not something you want to do unless there&#x27;s a lot of local support for it; it&#x27;s something that needs to be locally driven.<p>Maybe in São Paulo, there was such support, and in the end things worked out, which is great.<p>But if nobody actually cares, it would be pretty silly to do it simply because of a &quot;global movement.&quot;