Oh boy I love this thought. I think very bad of advertising in public spaces. Was there ever a public discussion on this topic before bill-boards became the norm. Even in semi public spaces, likes the 20 or so Dutch TV channels people receive I feel that it is reason enough not to own a cable connection at all.
But... I would not make it illegal, but very heavily taxed. Tax billboards for 95% out of this world because they are disgusting (that 5% might give us 50% of the current tax income), tax companies into only having small logo's on their buildings and into sponsoring events/art/archtecture/etc.
Focus, awareness, peace of mind, not selling out, "outside and inside come in pairs".
In my city, all billboards or outside ads over 25m² in size are banned. Bright lit billboards or animated billboards over 1m² are banned, too. (The area of the smallest enclosing rectangle counts).
Also, we have regulations on how much children TV shows and shows during the day may contain in advertising in my country, very helpful.
That's what I think as well: tax it. Problem is: it has become very hard to distinguish advertising from other forms of communications. I think there should be some form of blanket tax on all forms of communications (billboards, web, magazines, newspapers etc) and part of the tax income should be spend to compensate for the negative effects of advertising: i.e. educate people based on scientific facts and subsidise real journalists, public tv, quality newspapers.
Of course there is no good way of implementing this. Advertising happens on a worldwide scale and no government (except north korea, who have this problem under control already) can implement it. Besides: advertisers own politics, it will never happen.
But... I would not make it illegal, but very heavily taxed. Tax billboards for 95% out of this world because they are disgusting (that 5% might give us 50% of the current tax income), tax companies into only having small logo's on their buildings and into sponsoring events/art/archtecture/etc.
Focus, awareness, peace of mind, not selling out, "outside and inside come in pairs".