Your example of Google's ads precisely shows why there is no such thing as "acceptable advertising", because ads, like a gas, will expand to fill any space that

Your example of Google's ads precisely shows why there is no such thing as "acceptable advertising", because ads, like a gas, will expand to fill any space that is available to it. The only reason your city isn't blanketed in billboards is because a zoning authority of some kind has blocked it from happening. Google up to 2004 (pre-IPO): clearly marked and coloured ads, 1 on top, maybe 2 on the sidebar. Google now: No sidebar, first 5 results are ads, where the "Ad" label itself is barely visible.