The number of commercial breaks in one episode

[Moviefan2k4]

All I know about this is that to start with, most TV shows only had one break with a single sponsor for the program. But over the years, shows became so expensive that those in charge couldn't do it alone. So, in exchange for airing a promo during the program, each sponsor gave the production a certain amount of money to finance it. That's why you have 20 or so sponsors now, per episode. The average runtime used to be about 50 minutes, with a ten-minute sponsor ad afterward. But now, you're lucky to reach the 40-minute mark, or sometimes even 35. For example, episodes of Smallville generally ran from 36 to 43 minutes, depending on the amount of commercials. I know this because I used to tape them onto VHS, pausing to cut the ads out.