TV Ratings Thursday: ‘Big Bang Theory,’ ‘Young Sheldon’ and ‘Grey’s Anatomy’ dip slightly

This edition of the Masked Mailbox starts off with a simple question for CM that requires a long answer, but I'll try to condense it.
"Can you explain how Nielsen sweeps work and if they still matter?"
A broadcast network is made up of a combination of owned and affiliated stations who carry the network's programming in all the dayparts. These stations fill out the day with locally produced content (mostly news) and syndicated shows like "Judge Judy" and "Wheel of Fortune."
Nielsen has a national sample to measure network programming, but in order to determine ad rates for the local station, Nielsen would measure viewing in every market four times a year -- November, February, May and July -- by sending out diaries. Nielsen would collect the diaries and issue reports for every market in the country. This is how stations would get their demographic data.
Although the networks are evaluated every day through a national people meter sample, they load up programming during these sweep periods in order to give their affiliates the best possible ratings, which are then used to sell ads until the next sweeps period. The 10 p.m. shows are especially important because they lead into the station's local news.
Networks don't benefit directly from sweeps; their owned stations do. When I was in the biz, they were bragging rights for the highest-rated network.
Things started to change when more and more markets came online as people meter markets. Now stations in the largest markets receive daily demographic data, making sweeps periods obsolete.
I believe Nielsen still measures the smaller markets during sweeps periods, but maybe there's someone out there who can confirm that.
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The ever-inquisitive SH asks, "Friday night broadcast TV is interesting right now. Here you have ABC, which cancelled their comedy lineup at 8, and have lost several million viewers in the process. Also, why do networks keep putting on these Marvel shows? They never get viewers. I'm sure it has to do with other parts of the deal."
There is a long history in this business of cancelling shows and seeing ratings in the time period decline with new and different programming. ABC didn't completely own either of the comedies it axed and was probably losing money with them. "Once Upon a Time" is approaching the end of its career, and ABC felt that a show it owns can perform well enough in a low HUT time period.
Regarding the Marvel shows, it's a function of corporate synergy since Disney owns Marvel.
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... And he has a follow-up: "Not sure if you've seen the promos FOX is running for 'The 4.' I'd love to get your take. They literally say 'Who are the 4?' I'm wondering why that would make anyone want to watch.”
I have no idea.
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Have questions? I’ll answer them if you email me at masked.scheduler@gmail.com or tweet me @maskedscheduler.