Sweeps Weeks and Nielsen Ratings: There's something I don't understand

During sweeps weeks, the networks usually broadcast shows that would draw in the most viewers. This is the best time to catch the most amount of sex, violence and cussing on regular TV. Presumably, future advertising rates would depend on these ratings. What I don’t get is that ratings are constantly being monitored. Many publications report the most watched shows every week. So then why are sweeps weeks so important? If I was an advertiser, I’d pay up for consistent ratings and not extraordinary ratings that are not sustainable once sweeps weeks are over. Can someone explain?

Because of the…You see, it’s all due to the…um…

That’s a really good point. My guess is that it’s a holdover from a time when they didn’t monitor year round. Nowadays they take both sweeps and regualr programming into account. Networks haveto go nuts during sweeps or they lose the spike in ratings, driving their average down.

Just a WAG.

What Nielsen says: Sweeps are for setting local ratings/ad rates (because many advertisers are local not national), and the local ratings are only measured during sweeps.

Networks use ratings during the other times of the year to determine how their programming is performing, but the ratings during sweeps season determine advertising prices for the next several months. Thus, big ratings during sweeps equals big bucks.

How connected is Nielsen to the networks? Wouldn’t it make more sense to do “sweeps” unannounced? That would give you more representative information I would think.
Unless of course, Nielsen doesn’t want ratings to seem low.

This makes sense, although I’d figure that the progress in technology over the years would allow year-round monitoring for even local advertisers.