I think decline perdition is wrong in part (their will be decline in specific areas and for certain tackiness but growth in usage)
We are in a growing trend I think right now people over pay for unsure costumers and that potential traffic gets lost in the mix.
But with the factual growth and things like a google now having a top 20 ranked news source show growth.
As more and more buyers become online friendly I think you will see evolution in the form of advertising.
Simple exposure base cost $$ and the larger the base the more the $$ in PPC you still have exposure for all searches you are toped on this creates barding and label awareness (assuming you do brand yourself in those 2 short lines)
People = advertising cost if you buy a commercial what guarantee is their that you will get a turn on your investment.