Edward Wyatt at the New York Times has an article focusing on American Idol that ponders the mechanics of increasing revenues, even in the face of declining ratings. It's worth the read for anyone interested in those mechanics. I loved this blurb:
Even though the overall audience is declining, “American Idol” appears to be in little danger of losing its crown as the top-rated television series. In the 2003-4 season, the first in which “Idol” was the top-rated prime-time series, its lead over the second place show was about 7 percent. That margin has grown every year since and this year is 66 percent.
Mike Darnell, the president of alternative entertainment for Fox, who oversees “Idol” and other reality shows for the network, said that “Idol” could lose 12 percent of its audience every season and still be among the top 10 shows on television in 2016 — even if every other show on television maintained all of its current audience.