TV sweeps and advertising rates

As I write it is now sweeps time on TV. This is when the TV networks pull stunts to increase their ratings so they can raise their advertising rates. Good Morning America’s live birth bit this morning is a classic example of a sweeps stunt.

What I have never understood, however, is why sweeps are necessary, and why advertisers would pay for commercial time based on sweeps numbers. If Good Morning America, for instance, gets a large bump in the Nielsen ratings today due to its baby stunt, does that have any bearing on how many people will watch the show next Tuesday when it returns to its regular programming? Why should or would an advertiser pay for advertising on next Tuesday’s show based on the ratings today’s obviously gimmicky episode gets. The sweeps ratings are not representative of the show’s regular ratings, so why set ad rates based on them?

Furthermore, with regular Nielsen ratings released overnight why is it even necessary to have sweeps? The networks know what ratings their shows are getting and can charge accordingly.

If anyone can, please enlighten me as to why sweeps continue to exist and what purpose they serve. I just don’t get it.


There’s quite a bit of controversy over whether sweeps (or Nielsen data) still serve any purpose in the modern, fragmented TV/cable universe.

First things first, though:

–Sweeps do serve a purpose beyond “stunt” programming to attract higher ratings. They are the four periods of the year during which Nielsen collects more detailed information from more viewers in more markets. The overnights are OK, but they are based only on the 5,000 TVHH that Nielsen regularly measures. Sweeps ratings include larger amounts of data from diaries in all 210 television markets.

–Neither advertisers nor broadcasters are entirely stupid when it comes to setting rates based on sweeps. The rates they set are contingent on being able to reach a certain number of viewers. If the broadcaster stunts all through sweeps and sets rates on inflated numbers, then doesn’t deliver those numbers throughout the season, they’ll have to run make-goods for advertisers who aren’t getting the promised viewers or CPM. They don’t want to have to do that, believe me.

Still, there’s an argument to be made, what with satellite, cable, TiVo, and other devices abounding that Nielsen, as sophisticated as their monitoring equipment is, is not delivering accurate measurement numbers.

Still, all things considered, sweeps do serve one other important purpose: By collecting detailed data at the local market level, they help local stations to make decisions on what syndicated buys to make, show their news is placing in relation to others stations in the market, etc. The sweeps data is extremely important on that local level, and local ad rates based on that data are probably more reflective of reality than the network rates are.