The answers are:
-
It depends.
-
It depends.
-
It depends.
-
It depends.
There is no such entity as “cable.” There are thousands of networks, stations, companies, rebroadcasters, and variants thereof.
Commercial time is almost always priced by the expected audience. (The usual term is Cost per Thousand viewers, which is abbreviated CPM where M is from the Latin for one thousand. A thousand viewers may be a thousand individuals who see the ad once each or one individual who sees the ad a thousand times.)
That’s why ratings are so important. Advertisers need to have some objective standard other than the station’s word for how many eyeballs might be looking at the tv when the ad will be aired. The more eyeballs the higher the cost, right?
Not quite. Demographics count as well. If you’re pitching a new soft drink or sneaker, you don’t want a show that gets a primarily elderly audience. So what you want is the maximum number of eyeballs of the type you hope to sell to. So if there is a show that you expect teens to watch you put your commercial there and pay for the privilege, right?
Not quite. Although there are services like the airtime sellers you mention that monitor every cable service in the US for their schedule, it can be too complicated and expensive to precisely schedule an ad for 4:42 pm on Monday. Many advertisers will just purchase a set number of ads, say 1000, and have the broadcaster show them whenever there is a convenient slot, which is why you sometimes see the same ad twice over in the same commercial block. This is much cheaper, but less targeted.
But how does it work from the other side? Well, national networks and cable stations keep a number of ad minutes per hour for themselves so they can get the ad revenue for those minutes, but also allocate some minutes for local ads so that the local provider can feature spots and keep that portion of the money. These numbers vary from station to station, time of day, day of week, season of the year, and so forth.
But there are 24 hours a day to fill and programming can be expensive. It is a wonderful deal for stations to just sell off a half-hour block to someone else to fill. This is where infomercials come in. And again, the money charged varies according to the million variables I’ve already listed.
Then comes political ads, station promos, and all the rest of the junk that interrupts programming as much as 20 minutes per hour.
After that it gets complicated.