“people using the DVR to skip the commercials”
Which I do as well. And with FireFox, you can use the Adblock Plus addon to nuke most online ads. Years ago I would click an occasional google ad, but never bought anything because most of those advertising had poor prices, poor selection, and poor terms. I quickly realized there was a reason they had to advertise to appear on the first page of a google search!
We have the technology to track how well each add works, and they prices they can command have dropped as well. These ad revenues are what pays for TV. As they drop (and they will drop more), the quality and quantity of shows will drop also.
You can already see it in movies. The majority of movies are remakes or sequels, and even they are reaching the saturation point.
My sister says she expects a crash in the entertainment economy soon.