Is there any advertising medium that won't be overexploited? Some owners, especially small ones, of advertising real estate will always try to squeeze every dol

Is there any advertising medium that won't be overexploited? Some owners, especially small ones, of advertising real estate will always try to squeeze every dollar possible. A majority of small newspapers carry an overload of local advertisments. The problem that I see is — it's far easy to increase ads than to increase readership. The only solution I see is Google implementing strict policies to curb the menace. I am pretty sure it's in their technical prowess to implement ad placement restrictions but why aren't they doing it? Maybe, it's in their best interest financially to just be easy on the issue.